4) An Overview on Logistic Regression in ML

 An Overview on Logistic Regression in ML

Introduction:

                               This is a supervised ML algorithm and also known to solve the binary classification problems. Binary means two and classification means natures and this means that we use it, to predict the nature between two natures.  In simple words here we have two classes it can be true(presence) or false(absence) or may be 1 or 0,  Like Linear Regression problem which we discussed in blog 4, we give and input x and model (discuss it later) will predict output y. In of the point is false categories called negative class and true categories called positive class.

How to achieve Logistic Regression:

                             To Achieve logistic regression we use sigmoid function which gives us the value of 0 and 1. We apply condition here to get the prediction in 0 and 1 form like if f(x) which is output greater than 0.5 then real output will be 1 and if less than 0.5 then real output will be 0. This we cannot achieve if we start using the linear function for this kind of problem also like linear regression problems because linear function can give us the output in wide variety of numbers which can make difficult to get classification number like 0 and 1. 

Sigmoid Formula:

               

An overview of Logistic Regression with single neuron:

As you can see x is input which will multiply by weight(w) and add by bias(b) and sigma is activation

function sigmoid after applying sigmoid we will get the output y. Here after getting the output y we will compare thus output with the actual output if both are same or close then good we test this thing using the loss function if loss is less then good otherwise we will change the value of weights and bias using gradient decent. This we will do until we reach the closest value.

Loss Function Formula:

                         L(f w[ i ] ,b ) ,y1 ) =- ( yi ) log ( fwb ( x[i] ) ) - ( 1 - yi ) log ( 1 - fw[i] , b ( x[i] ) )

Cost Function Formula (Gradient Decent Formula):

                         J ( w[i] , b ) = 1 / m ( sigma ( L ( fw [i] , b ( x[i] , yi ) ) )

Notes:

Code:

from distutils.log import warn
import numpy as np
import matplotlib.pyplot as py
x_train=np.array([2,3,5,6,9,1])
y_train=np.array([0,0,1,1,1,0])
np.seterr(divide = 'ignore') 
# np.seterr(divide='warn')
def calculate(x,w,b):
    fx=np.dot(x,w)+b
    return fx
def sigmoid(z):
    fx=1/(1+2.71**(-z))
    return fx
def cost(x,y,w,b):
    m=len(x)
    t_cost=0
    sum_cost=0
    for i in range(m):
        fx=sigmoid(np.dot(x[i],w)+b)
        print("here is the issue ",fx)
        t_cost=-(x[i]*np.log(fx))-((1-x[i])*np.log(1-fx))
        sum_cost+=t_cost
    total_cost=(1/m)*sum_cost
    return total_cost
def gradientLoss(x,y,w,b):
    m=len(x)
    lossW=0
    lossB=0
    sum_loss_w=0
    sum_loss_b=0
    historyW=np.zeros(m)
    historyB=np.zeros(m)
    for i in range(m):
        fx=sigmoid(np.dot(x[i],w)+b)
        loss=fx-y[i]
        lossW=loss*x[i]
        lossB=loss
        historyW[i]=lossW
        historyB[i]=lossB
        sum_loss_w+=lossW
        sum_loss_b+=lossB
    sum_loss_w=(1/m)*sum_loss_w
    sum_loss_b=(1/m)*sum_loss_b
    return sum_loss_w,sum_loss_b

def gradient(x,y,w,b,lr,iterations):
    historyW=np.zeros(iterations)
    historyB=np.zeros(iterations)
    for i in range(iterations):
        gradientW,gradientB=gradientLoss(x,y,w,b)
        w=w-(lr*(gradientW))
        b=b-(lr*(gradientB))
        historyW[i]=w
        historyB[i]=b
    return historyW,historyB
def predict(x,w,b):
    result=np.zeros(len(x))
    for i in range(len(x)):
        output=calculate(x_train[i],w,b)
        if(output>0):
            result[i]=1
        else:
            result[1]=0
    return result    
        
    
w=0.1
b=1
lr=0.1
historyW,historyB=gradient(x_train,y_train,w,b,lr,1000)
print("Weights are ",historyW)
print("Bias are ",historyB)
w=historyW[-1]
b=historyB[-1]
# total_cost=cost(x_train,y_train,w,b)
# print("Cost is ",float(total_cost))

output=predict(x_train,w,b)
print("Output is ",output)
output2=sigmoid(np.dot(x_train,w+b))
print("Sigmoid output is ",output2)
py.scatter(output,output2,c='r')
py.title("Comparison")
py.xlabel("predict")
py.ylabel("sigmoid")
py.show()

    

    
    

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More operators, order, between, in, like and where clause

 

In this blog we will talk about some more operators which we can use in oracle SQL e.g not, or, and, >=, <=, <, >, =, <> etc. These are some more operators and how we can use them now we will understand this.

Before learning about these operators we should understand about where clause. As this name is showing the qualities of this clause that it uses when we want to filter the result also this we can use only with the select statement. Example to use this clause is given below

select ename from emp where empid=2;

Meaning: Meaning of this query is to find the employee name from employee table where employee if is equal to 2.

Use of the operators:

select ename, sal from emp where sal>2000;

select ename, sal from emp where sal<2000;

select ename, sal from emp where sal>=2000 or sal<=2000;

select ename, sal from emp where sal<>1000; (Not equal to operator)

This is how we can use these operators. There are also lot of the things which we can perform in oracle SQL.

Order:

We can also show the result in ascending or descending order and how we can use this is given below

select ename, sal from emp order by ename asc; (result will show alphabetically) 

select ename, sal from emp order by ename desc; (result will be show in descending order)

You can also check the result by copy the query and paste that queries to the SQL plus. 

Between, in, like:

As the name showing the meaning that between is uses to show the result between two inputs, In uses as or operator and like is uses to show the similar result for like. How we can use this examples are given below

1) select ename, sal from emp where sal between 1000 and 500; (this will show the salaries which are between 1000 and 500)

2) select ename, sal from emp where empid in(1,2,3); (this will show the ename and salaries for empid's which are 1, 2 or 3;

3) select * from emp where ename like'%R'; (this will show the results where enames end with R)

More about Like:

There are more things which are necessary to understand about the like operator so there are below

like'%R%'; (this will display the result for enames where names contain R in the center)

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3) Multiple Linear Regression

 Multiple Linear Regression

Here we have multiple features such as (x1,x2,x3...) instead of one feature (x1) and after feed these features to model we can get the output (y). Before proceeding away we should understand some of the terminologies which we use for ML. let's assume a[i][j] here will the help of j we can proceed toward columns and with the help of i we can proceed toward rows. Furthermore, n is the total number features.

How Model find value for Multiple Features:

let’s assume we have 3 features x1, x2 and x3 with three weights w1, w2, w3 and one bias b and by using these values we can find the output f(x).

f(x)= ((x1*w1)+(x2*w2)+(x3*w3))+b

After getting the f(x) value we go ahead by finding the loss with the help of loss function and apply gradient decent to get the right parameters (weight and bias) for the model. This all we will understand with time. But for now we should have little bit of understanding for basic terminologies, methods and approaches.

=> We have bias b, weights [w1,w2,w3..] and features [x1,x2,x3…]

=> Model f(x)= pred_y[ i ] =w1*x1+w2*x2+…+w(n)*x(n)

=> cost function J(w[i],b)=((sigma(pred_y[i]- actual_y[i]))²)/2m

=>update weight w[i]= w[i]- learning rate * ( J(w[i], b ) * x[i]

=>update bias b= b- learning rate * (J(w[i],b)

Note: Vectorization is good approach to perform any operation as compare to use loops

Here we have Model named as f(x) and with the help of model we predict our output (y). After predicting the value (y) we will find the error using cost function called Gradient decent. Our parameters will perfectly tuned if our cost function is close to zero. With the help of cost function we will find the cost between actual_y (output) and predicted_y (output). If our error is high then we will update the weight and bias and make the cost close to 0.

Feature Scaling:

In simple word this is normalization of independent features. This helps us make gradient fast. We use normalization if either feature difference is too small or too large. Therefore, in normalization we scale the values between 0 and 1 most of the case. We can take the example of images while training model for images we normalize the images to make training fast for model. There are too much types of normalization and mostly common two of them are given below

1) Z-Score Normalization: Here data (features) will normalize in such that mean of your data will be zero and standard derivation will become 1.

               Formula:          x1= ( x1 - mean( u1 ) ) / ( standard deviation )

2) Mean Normalization:   Here we normalize the data with respect to mean

             

               Formula:           x1= ( x1 - mean( u1 ) ) / ( max - min )

Note: Now a days features engineering is one of the most useful thing in ML because with the help of it we identifies news features for model

An overview Diagram of Linear Regression:

Notes for Linear Regression:

I made very simplified version linear regression Code (Python) which is given below:

import numpy as np
import matplotlib.pyplot as plt
xFeatures=np.array([2,3])
yFeatures=np.array([330,400])
# plt.scatter(xFeatures,yFeatures,marker='x',c='r')
# plt.title("Actual Values")
# plt.xlabel("Size")
# plt.ylabel("Price")
# plt.show()
lr=0.1
m=len(xFeatures)
def calculate(x,w,b):
    y=w*x+b
    return y
def cost(x,y,w,b):
    JSumWeight=0
    m=len(x)
    for i in range(m):
        f_wb=(w*x[i])+b
        JSumWeight=JSumWeight+np.power((f_wb-y[i]),2)
    totalCostW=(1/2*m)*JSumWeight
    return totalCostW

def gDecent(x,y,w,b):
    wid=0
    bs=0
    sumWeights=0
    sumBias=0
    for i in range(len(x)):
        f_wb=(w*x[i])+b
        wid=(f_wb-y[i])*x[i]
        bs=(f_wb-y[i])
        sumWeights+=wid
        sumBias+=bs
        
    sumWeights=(1/m)*(sumWeights)
    sumBias=(1/m)*(sumBias)
    return sumWeights,sumBias
            
def resultGDecent(x,y,w,b,iterations):
    recordW=np.zeros(iterations)
    recordB=np.zeros(iterations)
    for i in range(iterations):
        errorW,errorB=gDecent(x,y,w,b)
        newW=w-(lr*errorW)
        newB=b-(lr*errorB)
        w=newW
        b=newB
        recordW[i]=w
        recordB[i]=b
    
    return recordW,recordB

bias=1
weight=0.25
w,b=resultGDecent(xFeatures,yFeatures,weight,bias,1000)
print("1st Weight is ",w)
print("1st Bias is ",b)

# w,b=resultGDecent(xFeatures,yFeatures,w,b)
# print("Last Weight is ",w)
# print("Last Bias is ",b)
# w,b=resultGDecent(xFeatures,yFeatures,w,b)
# print("Last 1 Weight is ",w)
# print("Last 1 Bias is ",b)
getCost=cost(xFeatures,yFeatures,w,b)
print("Cost is ",getCost)
# plt.scatter(w,b,marker='x',c='r')
# plt.title("Actual Values")
# plt.xlabel("Width")
# plt.ylabel("Height")
# plt.show()
print("Our real value is ",xFeatures*w[-1]+b[-1])

Output:
After updating weights and bias we will have predicted value below
Our predicted value (y) is [328.882757 400.78734259]
You can check the actual y above in the code. For features x our model is predicting these values y after updating weights and bias with the help of gradient decent.
For Now this is enough. Today we learn some of the terminologies and functions which helps us for training model and updating weights and bias. We also see the basic code for linear regression.

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2) Linear Regression Model

 Linear Regression Model

This is the type of Supervised Learning Algorithms. Here we will predict a value after getting some inputs. We have some features x (if you have multiple features then x will become x1, x2, x3 and so on)as input. We will take these features and feed them to a trained model and our model will predict a value as output. In this way linear Regression Model works. Now let’s try to go in depth of model.

If we break the model as initial stage then it will be like this

Feature (x) — — — — — — — — → Model (f(x)) — — —— — — — -> Prediction (y)

Here f(x)= w*x +b, Maybe you are thinking what is this so let me explain. Here w is some weight, x is feature and b is bias. Let’s assume you bought 3 eggs (egg is feature) and price of a egg is 10 rupees (here price is weight and bias is 0(you can also take 1 as a bias). We know that weight and bias can be high or low according to the situation) Now let’s predict the price of egg as output by putting detail in the equation which we named as model

w=10; x=3; b=0

f(x)=w* x + b — — — — — — — — — -> 10 * 3 + 0 — — — — — — — — — -> 30 (this is prediction which we can say y)

Our actual price of eggs (actual-y) is 30. This means that we have 2 y’s first one is predictive y and second one is actual y. Predictive y denotes to that price which we predict by our own with the help of our model using that information which we have. And actual y denotes the actual or real price of eggs according to the market. After comparing the actual y with predictive y if both are near to each other means about the same then our model prediction is good if they are not same or near to each other then our model prediction is not good. Like other mathematic scenarios we should have some equation to measure this error between actual-y and predictive-y and here it is, to measure this error we have a method called cost function. formula is given below. 

Here n is number of training examples and Y[i] is actual value and Y^ is predicted value. We will put the values inside this function if output will be close to zero then our output is accurate otherwise we have to change the parameters (weight and bias) to make prediction accurate. Now maybe you are confusing how parameters (we are using parameter word for w and b)are changing, actually for training purpose when we are trying to train the model with the help of features x then we will check the actual-y with predictive-y at every iteration every error is high then we will change the weight and bias or update the weight and bias according to the situation. There are lot of the techniques to update the weights and bias for now you have to take the overview of the concept. We will cover the complete process how model trains itself in upcoming tutorials. At this stage you should familiar with Gradient Decent technique to update the weights and bias. Formula to update weight and bias using gradient decent is given below

Here alpha is learning rate which is also a parameter. You have to set the learning rate accurately. If Learning rate will be too small then weight and bias will update slowly toward target weight and bias (target weight and bias is that value where your model will predict the right output). If Learning rate alpha will have very large value them may be we cannot reach toward the target weight and bias. So you have to set the right value for learning rate so that our model will learn accurately and predict right value.

Example of Linear Regression using Single Neuron:

This Diagram shows the method of prediction that how model predicts the value. For today’s blog your understanding for predicting values should be clear.

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1) Machine Learning

 Machine Learning

Introduction:

Machine Learning is the subset of Artificial Intelligence. Now a days this is very buzz word. If you ask from anyone what do you want to become than most of the people answer it as Machine Learning Engineer. This is not easy as sound like here you have a huge grip on Math and stats to become a good ML Engineer. Actually, This is explicit program which Help us to get label or predict label, recommend videos to anyone according to his/her searching data, predict spam email or not etc. There are various things which are using Machine Learning such as  Self Driving Cars, Speech Recognition Systems and Google Maps etc. There is another buzz word called General AI which helps us to act the AI like Humans.

Machine Learning Types:

ML is explicit program to create intelligence e.g while playing checkers ML Algorithm works better as much as ML Algorithm gets the Data. There are some types of Machine Learning Algorithms which are Given Below: 

1) Supervised Learning (It is using in real life applications)

2) Unsupervised Learning

3) Reinforcement Learning

4) Recommendation Systems

We will choose the right tool for a specific problem after identifying the problem and after getting identification we can select the right algorithm.

1) Supervised Learning:

About 99% problems are solving now a days using supervised learning. e.g

                    => email     ------------->        spam(0/1)       ---------->              spam filtering

                    => audio     ------------->        text transcripts         --->              speech recognition

                    => English  ------------->        Spanish        ------------>              Machine Translation

                    => ad, user info    ------>        click(0/1)         --------->              online advertising

                    => image, radar info  -->       position of other cars  ->              self driving cars

                    => image of phone  ---->       defect(0/1)      ---------->              visual inspection

Regression and classification are the type of supervised learning. 

  => classification  problem predict categories (it should not be number). For example you are classifying the two categories for email like spam or not spam. You can say class A is spam and class B is not spam. In classification problem your model will be able to tell the difference between these two classes after training. You should not limit the categories I choose the example of binary classification because here we are dealing with 2 classes which are spam(1) and not spam(0). There can be multiple classes in the classification problem. (Here I have one of the most important point which is your model can only understand the numbers. You have to convert everything into numbers e.g images, text). Here we also have to convert the categories into numbers like 0 and 1 if you have more than one category then convert it into 0,1,2,3 on so on. This is really a fun.

  => Regression problems predict the infinitely possible numbers. This is also one of the famous type of supervise learning. Here we can take the example of House Price Prediction System where you have to estimate the price of the house and this can be infinite possible numbers. Here you are not dealing with categories or classes here you are dealing with numbers. You will feed the training x features (features are attributes of the house like location, size, rooms, bathroom etc.) to the model with training y feature of the model price. After feeding the data your model will start finding the pattern by adjusting the parameters weight and bias(we will see the whole mechanism later in the blogs which can help you understanding the whole mechanism). Here weights and bias will adjust in this way that when features x will multiply by weight (w) and add with bias (b) you will get your predicted price (y=w*x+ b). I know this is little bit hard to understand at this stage but don’t worry we will cover every thing in detail later. We will also understand the model training mechanism, testing mechanism ans so on. I will also provide you the code which can help you for better understanding.

2) Unsupervised Learning:

Here we find something interesting with unlabeled data e.g clustering, k-mean etc.

Note: Google also use clustering in Google News to show related articles by finding similar tags or words.

Here you do not has input x with output y to train model so here we find structure in data by clustering, anomaly detection(find unusual data points), dimensionality reduction(compress big data set to small one using fewer number).

Note: Remaining two types of Algorithms we will write in upcoming tutorials

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Operation of Hello World c++

 

[C++ is case sensitive language means if we will use upper case letter at the place of lower letter in the syntax then program will generate the error.] 

Here is the article related to c++ programming. Firstly we will check the simple Hello World program and then break that program into pieces and then check the every line and its use in the program

       
#include<iostream>
using namespace std;
int main()
{
cout<<"Hello World"<<endl;
return 0;

This is the program which will display the message "Hello World". Now we will break this program into pieces.

1) #include<iostream>

This is called header file in c++. We uses different kind of header files to access the different functionality of c++. This is like the key to access the treasure. In simple words if we want to access the specific file then we uses header file. In the above program I used iostream header file which is uses to take input or display the data or for basic functionalities such as to break line etc.

2) Using namespace std;

Actually the complete syntax of c++ is like

 "std::cout<<"Hello World"<<std::endl;"

 (in this way use std:: with every object used from specific header file)

 this syntax will become little bit difficult to implement therefore, we use using namespace std and this will automatically apply the std with every object of header file and in this way it will become more easy to use. 

Note:  

do you focus here at the end of the line I used a semi column(;) this we use to tell the compiler that we had end the line.

3) int main()

we can also use void at the place of int. Actually, we use main as a driver of the program like a car. Main should be compulsory in a program because without main program cannot run also every program always start from main. Moreover, this is more like a function which should be compulsory in a program. May be, in this stage you are not familiar with functions so, don't worry we will learn in our next lectures.

Note: After using int main() we will also define the scope for main by using the bracket({). If you don't know how to define the scope then answer is you can define scope like this { here you can write the program part}.

4) cout<<"Hello World"<<endl;

This is the main line to display the hello world as a output. Here I used cout and endl. cout is uses to display the data and after writing cout we need to use stream out operator(<<) and then use "Write string or message here" and then again stream out operator(<<) and then I used the endl to break the line. In this way I display the message as a output.

5) return 0;

We use return 0 when our main is of int type because int always return an integer at the end of the function. But if we will use void as the return type of main then it will return nothing at the end of the function.

In this way program works here. Now, you can try different experiments for this program to understand the behavior. 

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How to develop logic?

 Logic Development

Have you heard programmer is nothing without logic? If yes then you should definitely read this article to which can help you in development of logics.

Before some practices we should understand what is logic? can you answer this question? you should answer if you don't know then don't worry I will answer you. "The ability to solve any problem". If you know better answer then you can comment below this will also increase my understand related to logics. So what ever, now I should come to point that how to develop logic?

How to develop

 Here please try to answer these questions.

1) How can you add 2 odd numbers to get even answer?

Answer:

Yes I know answer is too simple and definitely you had answered this question but I should also contribute my answer which is add 1+1 =2(odd +odd=even) . This is called logics and by solving these kinds of problems you can enhance you logics. Now try to solve question two.

2) Now try to solve by adding 3 odd numbers to get even answer?

Answer:

This is called logic now may be you are confuse here and may be your answer will be this is not possible but here I did not limit you, you can use any of the method to solve this question.

Hint: you can also use decimal numbers.

May be now you can solve this question. If not then don't worry I will tell you so the answer is 

5 + 3.9 + 1.1 =10 (odd + odd + odd= even).

Now, you had learnt the solution of another problem and do you know the meaning of it. Meaning of it, is you had develop your logic by solve these complex problems. Now you have to add this logic into programming (these are the sets of instructions which a machine follows to perform any task). If I will tell you to define that question 1 into the set of instructions. you can use any language to define instructions and at the same time I will also solve this question and answer is below

1) initialize three variables one for first number, second for second number and third for answer 

2) Now assign the first two variables with number

3) Now, add the first two variables and store the answer into third variable

4) Now you can display the answer.

I will solve this question in this way you can also use your own way to define instructions also you don't need to use the line of initialize or assigning because you don't know the meaning of it because now you are beginners. We will learn this in the next blogs.

Tips to improve Logic

1) Solve critical problems

2) try to solve same problem with different ways

3) Play logical games such as Castle Crash or Candy crash etc

4) Critical Programming practices is one of the best way to improve logics.

There are tons of others ways which can improve your logics but these are the only one's which are on my mind which I had shared.

Stay connected for more these kinds of articles.

 

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Routers and Hyper terminal configuration

 

Q1: Introduction to Router and establishing a console session Using HyperTerminal.

Tasks:
 
1.       Router Introduction
2.       Devices Connectivity
3.       Router Ports and internal Memories details
4.       Hyper Terminal Configurations

 

Routers:

                Router is a network device used to make the connection between two or more different networks and also work in network layer. Also the purpose of router is to forward the data packets and select the best path from routing table. There is lot of the companies which creates router but Cisco is on top. There are three level hierarchy of Cisco table first is access layer routers which are cheapest and for small organizations, second is Distribution layer table which is costly then Access layer routers and more advance then Access layer routers and third last one is Core layer routers which is known as backbone routers because these are the best routers and used by global ISP’s.

 

Device Connectivity:

 

There are two routers which are connected together by using wire and these both of them have joined two peer to peer networks.  In this way router connects the networks.

 

Router Ports:

                      There are three kinds of ports on router

 

1)      LAN

2)      WAN

3)      Administrator

 

 

LAN:

        This is the port where Ethernet cables connect also there are Ethernet ports, fast Ethernet ports and Gig Ethernet ports in LAN. These all are connect through RJ45.

 

WAN:

          The port which connects WAN is called WAN port. This has lot of the serial ports and every serial port has two categories one is 26 pins and other is of 60 pins.

 

Administrator:

                       It has two kinds of ports one is local administrator (Consol) and second is remote administrator (Auxiliary).

 

Local Administrator:

                              This is also known as Console port and this is used for initial configuration, password recovery and local administration also it only caries the command. Furthermore, one side of console or rollover cable has RJ45 and other side has 9 pins com port.

 

Remote Administrator:

                            Remote Administrator port also known as Auxiliary port in this port console or roll over cable uses. Moreover, one end of this cable has RJ45 and other side has DB-25.

 

 

 

Memories Details:

                        It has four types of memories e.g Flash Memory, ROM, NVRAM and RAM.

 

ROM:

           Rom is a memory which helps to load IOS and also helps the router in starting and maintaining. It contains a program written in bootstrap which helps the router to load the IOS.

 

RAM:

         It helps to manage temporary configurations, routing table etc. Also while booting IOS loads in the RAM from flash.

 

Flash Memory:

             Flash Memory is the permanent memory which keeps the IOS. This system will not erase when router will reset.

NVRAM:

         This is also a kind of memory which erases nothing when router restarts or turns off.  It also configures mean ip addresses, passwords and routing table. Furthermore, it holds the configuration between routers and switches.

Hyper Terminal Configuration:

                                    Hyper terminal is a program used to send or receive the files between your computer and a remote computer over a modem.  This is a program like CMD and we can configure hyper terminal using different commands.  Hyper terminal is available in every window’s version onward from 2000. We can configure different devices using hyper terminal configuration eg if we want to configure router then we can will join the router with a computer by using a pc by using console wire and after this we configure the router by using hyper terminal in this way.

 

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Learn C++

We are starting the introduction of c ++ but before starting this we should talk about why we should learn c ++ as a first language. Mostly student ask this question, they thinks why c ++ and why not python because python is the most emerging language also easy to understand in the beginning but this is really an huge language we should not take start with it firstly we should develop some logic and we should understand how really programming works then we should shift to python. So whatever our question was why c ++? So answer for this question is c ++ is too old language also this language really tells the definition of the programming because in modern languages we don't need to initialize the variable or these kinds of things because scientists are trying to make the languages more simple to use therefore they are introducing the different libraries for the ease of the programmers therefore beginners can feel little bit difficulty to handle this because they cannot understand in more depth that how this program is really works. Therefore, c ++ providing the complete syntax for the programming. This was the first point that why we should learn the c ++ as a first language. Now the second point is c ++ is very powerful and very fast language because this is more close to the processor because c ++ directly access the Memory and this is the only one language which can access the Hardware directly this is the reason we use c ++ to develop game engines. If any person can get grip on this language then he can also earn a big amount of money by developing games or game engines. Mostly people thinks c++ is on the ending stage but reality is, It is an evergreen language because this is the fastest high level language. We should not underestimate this language. Furthermore, A good thing is this mostly big organizations ask the questions related to c++. After learning this language you will be able to develop management systems, Emended systems, heavy games etc. 

 Furthermore, c++ has two types of programming one is procedural oriented which is the programming with the help of functions and second is object oriented programming which we access by using classes and objects with functions. We can also use data structures in this language. Now you can imagine how big is this language. Also we cannot learn this complete language in our entire life because this is about 40 to 50 years old language and in 40 to 50 years the growth in this language is too high. Most of the programmers take start from c++ but now it's on up to you what do you want to select c++ or any other language. Here is the big thing which I am thinking right now which is some students who want to go in web developing so If you are reading this then this article will be not for you sorry!

Because in the beginning you should definitely go with html then css and then JavaScript etc. I am suggesting c++ to them who want to become software engineer or any kind of developer. If you want to go android development then you should learn java after learning c ++ but you can also learn java first because there is not too much difference in both the language first difference is of syntax and second is java is most efficient for android development and c++ for game development. Now we should talk about the most important part of the article which is topics to learn in c++.

1) Flow Diagrams

2) Variable and initialization

3) If-Else conditions

4) Loops

5) Arrays

6) Functions

7) Recursion

8) File handling

9) Pointers

There are lot of other topics to learn in c++ but these are the main topics to learn procedural oriented programming for c++. So After learning this you can also learn the object oriented part for c++. I will write the whole article on opp so stay connected with dowaste.

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Sample Feasibility Report

(there is the sample feasibility report)

(do not copy any of this content or idea because all rights are reserved)

Summary:

                        So In this feasibility report I will explain everything which is need in any feasibility report. This report will explain the product with Industry, organization and financial feasibilities. Also this report will tell you how this product going to help those people who want to exchange their product with any product or money.

Product:

                  So, we are going to provide the platform where you can exchange your product. For example if you have Samsung Galaxy j5 Mobile and your want to get the mobile with the new model also you are ready to pay something with your mobile then you can place a ad and if anyone on this platform is interested to buy your mobile then he can contact with you. In this way you can buy a mobile with a new model. May be now you are thinking why a person will get the old model phone with some amount of money instead of a new model then the answer is it is a good deal instead of selling the whole phone. Now I am going to explain this in detail, so if any the person who has new model want some money and therefore he is ready to sell his phone and he is thinking after solving the problem I will buy a cheap phone. But he got a good deal here he got the enough money from here which can solve your problem with the old model phone. Not only this can you also sell your product with money also because there are three ways to buy a product which is product to product, product to product with money and product to money. You can choose any of them.

Also a good thing in our platform which is that, after placing the ad it will review by our team. In the beginning we will use our team to review the product but after the growth of our platform we will place an program at the backend of our website which will review the product like a YouTube which review the video after uploading to check that is there any copyright part or not. In the same we will review the product to reduce the spam.

How this Product is different:

                                                             The thing which makes it different than any other platform it is the product exchange program. First of all yes this is also an e commerce website but different than any other platform because other platforms sell product at the place of money but we are also offering the customers to buy a product at the place of product or product with money.

Surveys:

                  The basic purpose to conduct the surveys is to get the review about the product that is it useful or not. In the same way we get the reviews from some people that is our product is useful then the answer of them were yes. Our reviews are also around yes. We are also founding our product useful because this is a unique online platform. We are the first one who is starting this. Also there are lot of the people who are searching this kind of platform especially people related to middle class families.

 

Industry or Target Market feasibility:

                                                   Here we will answer some questions related to the earning source and target market or people. So, firstly we should talk about the earning source and answer is here. Earning opportunities for this business are too much such as we can place ads here in this website from any ad agency such as Google ad sense, Surfe.be etc also we can earn by affiliated programs e.g we can place the products from affiliated etc. Our main source of income will be from the customers who will use our platform to exchange the product. We will charge them a little amount to use our platform but this we will do after a time when we reach to our desired audience. Firstly we will offer our platform in free of cost.

 Now, we should talk about the target market that which kind of audience we want. According to our views middle class people will going to use this platform more as compared to other people because mostly they sell their product if they need money urgently. But overall this will be worldwide service because everyone can access this service but the only thing to deal with this traffic is a big management which need time to build up. Therefore we will start this from a small scale which we will talk in the Management section of Organizational feasibility.

Organizational Feasibility:

                                            Here in the organizational feasibility we will talk about the resources and Management of our Business. Firstly we should talk about the Management system for our website. So because this is actually the website therefore we will face less management related problem as compared to any physical business problems because in online we will not have any kind of fear related to the stealing of products therefore we don’t need any kind of cameras and people to handle cameras, we don’t have fear related to the security guard for our store or website, we don’t need people to handle the customers so therefore the online business needs less management as compared to the physical business. Now coming to point that from where we will start our services. Before explaining this I will explain how our store will work so for example a person place an product our one of the team member will check the product that is it a fake customer or not. Now this question is arising how we will confirm it that is this real customer, answer for it is we will track the location and design the questions while placing the product in this way that we can caught a fake customer. E.g If any customer is belongs to Johar town, Lahore and placing the order while placing an order then we could ask them the question related to the nearest place etc. We will also include this privacy that this is necessary to place an order from home because we are tracking the location after this we will be able to identify the real one with fake one, now here is the question related to privacy concerns but we will not show this location to that buyer. The main purpose to get the location to stop fake customers also If you want to exchange the product from home then we can also provide you this service by using your location.
There are also other solutions related to privacy issues which we will implement in our website.

Now we will talk about the resources which are needed in our store. First of all this is an online platform which only need a domain, a website with hosting and few team members to manage this website.  Except of them the most important thing is the customers which we need. And to get the customers we will need marketing for our website which we will also use.  These are only the resources which we need.

Financial Feasibility:

                               Now we should estimate our financial report. Here now we will estimate the beginning start up cash so starting with a domain and hosting which is about 30 dollars per year. After this we need a website, as we are student of computer science therefore we don’t need any money to develop a website because we know how to make a website using word press. After this we need customers to place the products which are most important thing. So to complete this requirement we have many solutions such as we can promote our website, second way is this we can buy some products to place them to our website also we can say our relatives, friends and family to place products on our website. Our complete focus and money will spend on to get the customers from the internet.

So overall start up cost is about 30 dollars and the rest cost will spend on the marketing which we cannot include in the startup cash because spending money on marketing is like to put the water in the Ossian. So this is the financial report to start this business. 

 

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Operators and Precedence in Oracle SQL

 

Operators

We can also use the operators while writing the queries eg +, -, *, / and ^. By using these operators we can display output in more accurate way for example if the salary for the employee is 500 per month and we want to display this salary for an year then by using the operators we can easily display the output. We can solve this query by multiplying the monthly salary with 12 months. After calculating output will be 500*12 =6000. 

Do you solve this?

2*3/5+1 

Maybe some people who did not know about the precedence of the operators they cannot solve this question . Therefore, I can help those people who do not know about the precedence of the operators.

Precedence of Operator:

                             *,/ has the same precedence and +,- has the same precedence which works from left to right. If we talk about the complete precedence then this will be like braces then power then divide and Multiply (works from left to right), plus and minus (works from left to right) .

So by following this precedence we can solve ever equation in Oracle SQL. Now we should solve the above equation which is 2*3/5+1.

Here firstly we will solve multiply part and solve it equation will be like 6/5+1 now we will solve division after this equation will 1.2+1 and after adding answer will be 2.2. I can also provide the screen shot for this question on SQL Plus. So the answer is

Here may be you are thinking what is dual don't worry dual is a dummy table which we uses in Oracle SQL for the answer. We can use this table when we are not dealing with the physical table in database. SO this was for today and stay connected with dowaste for more concepts related to Oracle SQL.

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Select Statement and Distinct Keyword

 

Select Statement:

So this is the first blog related to oracle SQL. Today lecture will about the select statement which is one of the important topic in Oracle SQL. It is used to retrieve(show) the data. For example there is employee table in the database and by using select statement we can show the whole data which is present in the table. So here is the query related to select statement.

e.g

select * from emp;

Here * is use as whole. If I will translate this query in simple words  then the meaning of this query will be select or show the whole data from employee table. If I will use this query than output will be this kind.

In this way we can use the select statement to show the output from database.

Distinct Statement:

Distinct is the keyword which will become statement when we use select with it. We can use distinct keyword only with select statement. Now here question is arising why we use distinct keyword?

Answer for this question is, if there is any duplicate name or value etc in the table then we use this keyword. By using this keyword we can remove the duplicate names or any value from the table. Here I will also provide you the example to use this.

If I will use

select distinct ename from emp;

If I will translate this query in simple words then this query is saying that select the ename values without duplication and the output for this query will be this kind.

In this way we can use select statement and distinct keywords. This is enough for today If you need more about oracle sql then visit the SQL section from manu.

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Peer to peer Network with different sharing's

 

 Building and testing a Peer-to-Peer network

Tasks:

 

1.    Introduction (IP Assigning)

2.    Data Sharing

3.    Internet Sharing

4.    Resource Sharing

 

 

 

Introduction (IP Assigning):

Peer to peer connection is the directly connection between two or more pc’s. Here there is no server because every pc is itself acting like a server. Now I will create an example of peer to peer network and tell you how to assign IP to them.

So this is peer to peer network and now to assign IP to them we will click on any computer to assign it an IP after clicking on it click the Desktop button from Manu after this click on IP configuration and now you can assign any IP in IPv4  section and after assigning the IP hit the Enter.  In the same way you can assign IP to every computer.

 

Data Sharing:

You need to do some steps to share the data

1)      Connect two or more pc’s with the Ethernet cable

2)      Assign the IP addresses to them

3)      Disable the Window firewall

4)      Enable network sharing

5)      Verify the connectivity by ping command

6)      Now you can share the data

 

Internet Sharing:

To share the internet you should follow these steps

1)      Connect the client with host using Ethernet cable

2)      Go to the view network connections

3)      Now enable the internet sharing and  turn the sharing option to Ethernet

4)      Now close this window and come back to view network connection window

5)      Here you should assign the IP address in Ethernet option

6)      Now go to client computer and go to the same view inter sharing

7)      Here find the Ethernet option and assign here the same IP address as given to the host.

8)      Now you can surf internet.

 

Resource Sharing:

To share resources between peer to peer connection we need to follow the following steps

1)      Connect the pc’s with Ethernet cable

2)      Turn off the firewall

3)      Configure IP address

4)      Now make the Home group

5)      Now change the setting by go to the properties of your drive and change the sharing setting

6)      Now you can share the resources

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