IT and Business Application lab : Assignment 2

Problem 1

a) Create two matrices

Solution:            

Command

> a<- c(1,2,3,4,5,6,7,8,9)

> b<- c(32,48,1,5,10,12,15,18,23)

> dim(a)<- c(3,3)

> dim(b)<- c(3,3)

> a

     [,1] [,2] [,3]

[1,]    1    4    7

[2,]    2    5    8

[3,]    3    6    9

> b

     [,1] [,2] [,3]

[1,]   32    5   15

[2,]   48   10   18

[3,]    1   12   23  

b) Select 3rd column from first matrix {a} and 1st column from second matrix {b}

Solution:

Command

> a1<-a[ ,3]

> a1

[1] 7 8 9

> b1<-b[ ,1]

> b1

[1] 32  48 1

c) Combine the two matrices

Solution:

Command

> combine<-cbind(a1,b1)

> combine

     a1 b1

[1,]  7 32

[2,]  8 48

[3,]  9 1

Problem 2: Find the product of two matrices

Solution:

Command

> multiple<- a%*%b

> multiple

     [,1] [,2] [,3]

[1,]  231  129  248

[2,]  312  156  304

[3,]  393  183  360

Problem 3: Find the regression using nifty data from 01 Dec 2012 to 31 Dec 2012 ?

Solution:

Command

> nifty<-read.csv(file.choose(),header=T)

> open<- nifty[ ,2]

> high<- nifty[ ,3]

> data<- cbind(open,high)

> reg1<-lm(high~open,data=nifty)

> reg1

Call:

lm(formula = high ~ open, data = nifty)

Coefficients:

(Intercept)        open

  1578.3358       0.7355

Problem 4: Generate and plot a normal distribution curve

Solution:

Command

> x<-seq(0,100)

> y<-dnorm(x,mean=50,sd=5)

> plot(x,y,type="l")