Program 14

Program 14

Develop a r program to calculate and visualize a correlation matrix for a given data set, with color coded cells indicating the strength and direction of correlations, using ggplot2 geom_tile function.

library(ggplot2)
library(tidyr)
library(dplyr)

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

data<-mtcars
head(mtcars)

                   mpg cyl disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

cor_matrix <- cor(mtcars)
cor_df <- as.data.frame(as.table(cor_matrix))
head(cor_df)

  Var1 Var2       Freq
1  mpg  mpg  1.0000000
2  cyl  mpg -0.8521620
3 disp  mpg -0.8475514
4   hp  mpg -0.7761684
5 drat  mpg  0.6811719
6   wt  mpg -0.8676594

ggplot(cor_df, aes( x=Var1, y=Var2, fill=Freq))+
  geom_tile(color = 'white')+
  scale_fill_gradient2(
    low = "blue", mid = "white", high = "red",
    midpoint = 0, limit=c(-1,1),
    name="Correlation"
  )+
  geom_text(aes(label = round(Freq,2)),size=3)+
  theme_minimal()+
  labs(
    title = "Correlation",
    x="",y=""
  )+
  theme(axis.text.x = element_text(angle=45,hjust=1))