Prediction Using Linear Regression

 Practical 8: Prediction Using Linear Regression

Step1:

x <- c(151, 174, 138, 186, 128, 136, 179, 163, 152, 131) 

y <- c(63, 81, 56, 91, 47, 57, 76, 72, 62, 48) 

# Apply the lm() function. 

relation <- lm(y~x) 

print(relation)

Step2:

x <- c(151, 174, 138, 186, 128, 136, 179, 163, 152, 131) 

y <- c(63, 81, 56, 91, 47, 57, 76, 72, 62, 48) 

# Apply the lm() function. 

relation <- lm(y~x) 

print(summary(relation))

Step3:

# The predictor vector. 

x <- c(151, 174, 138, 186, 128, 136, 179, 163, 152, 131)

# The resposne vector. 

y <- c(63, 81, 56, 91, 47, 57, 76, 72, 62, 48)

# Apply the lm() function. 

relation <- lm(y~x) 

# Find weight of a person with height 170. 

a <- data.frame(x = 170) 

result <- predict(relation,a) 

print(result)

Step4:

# Create the predictor and response variable. 

x <- c(151, 174, 138, 186, 128, 136, 179, 163, 152, 131) 

y <- c(63, 81, 56, 91, 47, 57, 76, 72, 62, 48) 

relation <- lm(y~x) 

# Give the chart file a name. 

png(file = "linearregression.png") 

# Plot the chart. 

plot(y,x,col = "blue",main = "Height & Weight Regression", 

abline(lm(x~y)),cex = 1.3,pch = 16,xlab = "Weight in Kg",ylab 

= "Height in 

cm")

# Save the file.

dev.off()