program 15

Author

srushtivh 1nt23is218

Create multiple histogram using ggplot2::facet_wrap() to visualize how a variable is distributed to different groups in a built-in R dataset.

step1:load the librarys

library(ggplot2)

step2:load the in-built dataset

data(iris)
head(iris)
  Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa
3          4.7         3.2          1.3         0.2  setosa
4          4.6         3.1          1.5         0.2  setosa
5          5.0         3.6          1.4         0.2  setosa
6          5.4         3.9          1.7         0.4  setosa

step3:creating histogram layer

ggplot(iris , aes(x= Sepal.Length))+   geom_histogram(binwidth = 0.3 ,fill = "skyblue",color ="black")+   facet_wrap(~Species)+   labs(title="distribution of sepal length by species",        x = "sepal length(cm)",        y = "frequency")+        theme_minimal()

Develop an r function to draw a density curve representing the probablitlity density function of a continuous varaiable,with seperate curves for each group,using ggplot2.

step1:load the necessary libraray

library(ggplot2) 

step2:define the function

plot_density_by_group <- function(data, continuous_var , group_var , fill_colors = NULL){    
  if(!(continuous_var %in% names(data)) || !(group_var %in% names(data))){      stop("invalid column names.make sure both varaiables exist in the dataset.")   
    }  
  p <- ggplot(data,aes_string(x = continuous_var , color = group_var , fill = group_var))+    
    geom_density(aplha = 0.4)+    
    labs(title = paste("density plot of",continuous_var,"by",group_var),          x = "continous_var",          y = "density")+  
    theme_minimal()  
  if (!is.null(fill_colors))   {   
    p <-p+scale_fill_manual(values = fill_colors)+      
      scale_color_manual(values = fill_colors)  
}  
return(p)
}

step3::Load dataset

data(iris)
head(iris) 
  Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa
3          4.7         3.2          1.3         0.2  setosa
4          4.6         3.1          1.5         0.2  setosa
5          5.0         3.6          1.4         0.2  setosa
6          5.4         3.9          1.7         0.4  setosa

step 4: call the function with example

plot_density_by_group(iris,"Sepal.Length","Species")
Warning: `aes_string()` was deprecated in ggplot2 3.0.0.
ℹ Please use tidy evaluation idioms with `aes()`.
ℹ See also `vignette("ggplot2-in-packages")` for more information.
Warning in geom_density(aplha = 0.4): Ignoring unknown parameters: `aplha`

To generate basic box plot using ggplot2,enhanced with notches and outliers and grouped by a categorical variable using an in-built dataset in R.

step1:load the required package

library(ggplot2)

step2:load the built-in dataset

data(iris)
head(iris)
  Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa
3          4.7         3.2          1.3         0.2  setosa
4          4.6         3.1          1.5         0.2  setosa
5          5.0         3.6          1.4         0.2  setosa
6          5.4         3.9          1.7         0.4  setosa

step3:adding graph/layer

ggplot(iris,aes(x= Species,y = Sepal.Length))+
  geom_boxplot(notch = TRUE,outlier.colour = "red",outlier.shape = 16,outlier.size = 2, fill="pink")+
  labs(title = "box plot",
       x ="Sepal.Length",
       y = "Species")+
  theme_minimal()

12.develop a script in R to create a violin plot displaying the distribution of a continuous variable,with a separate violins for each group using an inbuilt dataset.

step 1:load the library

library(ggplot2)

step 2: Grouping variables

mtcars$cyl <- as.factor(mtcars$cyl)

Step 3: Create a violin plot

ggplot(mtcars, aes(x=cyl, y=mpg, fill = cyl)) + 
  geom_violin(trim = FALSE) +
  labs (  title = "Distribution of MPG by Number of Cylinders", x= "Number of Cylinders", y = "Miles Per Gallon (MPG)" )+ 
  theme_minimal()

Write a R program to create many dotplots from the grouped data.comparing the distribution of varaiables across using ggplot2’s dodge position function

step1:load the library

library(ggplot2) 
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("ToothGrowth")

step2:load dataset

head(ToothGrowth) 
   len supp dose
1  4.2   VC  0.5
2 11.5   VC  0.5
3  7.3   VC  0.5
4  5.8   VC  0.5
5  6.4   VC  0.5
6 10.0   VC  0.5
table(ToothGrowth$dose) 

0.5   1   2 
 20  20  20 
class(ToothGrowth$dose)
[1] "numeric"
summary(ToothGrowth)
      len        supp         dose      
 Min.   : 4.20   OJ:30   Min.   :0.500  
 1st Qu.:13.07   VC:30   1st Qu.:0.500  
 Median :19.25           Median :1.000  
 Mean   :18.81           Mean   :1.167  
 3rd Qu.:25.27           3rd Qu.:2.000  
 Max.   :33.90           Max.   :2.000  
ToothGrowth$dose <- as.factor(ToothGrowth$dose)
ggplot(ToothGrowth,aes(x=dose,y=len,color=supp))+
  geom_dotplot(binaxis = "y",
               stackdir = "center",
#which direction to stack the dots. "up" (default), "down", "center", "centerwhole" (centered, but with dots aligned)
               position = position_dodge(width = 0.8),
               dotsize = 0.8,   
#The diameter of the dots relative to binwidth
               binwidth = 1.5)+#controls spacing of dots on y axis
  labs(title="tooth length dose by suppliment type",
       x = "Dose",
       y ="length",
       color="supplement")+
  theme_minimal()

Develop an r program to calculate and visualize a co-relational matrix for a given a dataset,with color coded cells indicating the strength and direction of co-relations,using ggplot2 geom_tile function.

Step1:Load the library

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

step2:load dataset

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
data(mtcars) 
cor_matrix <- cor(mtcars) 
cor_matrix 
            mpg        cyl       disp         hp        drat         wt
mpg   1.0000000 -0.8521620 -0.8475514 -0.7761684  0.68117191 -0.8676594
cyl  -0.8521620  1.0000000  0.9020329  0.8324475 -0.69993811  0.7824958
disp -0.8475514  0.9020329  1.0000000  0.7909486 -0.71021393  0.8879799
hp   -0.7761684  0.8324475  0.7909486  1.0000000 -0.44875912  0.6587479
drat  0.6811719 -0.6999381 -0.7102139 -0.4487591  1.00000000 -0.7124406
wt   -0.8676594  0.7824958  0.8879799  0.6587479 -0.71244065  1.0000000
qsec  0.4186840 -0.5912421 -0.4336979 -0.7082234  0.09120476 -0.1747159
vs    0.6640389 -0.8108118 -0.7104159 -0.7230967  0.44027846 -0.5549157
am    0.5998324 -0.5226070 -0.5912270 -0.2432043  0.71271113 -0.6924953
gear  0.4802848 -0.4926866 -0.5555692 -0.1257043  0.69961013 -0.5832870
carb -0.5509251  0.5269883  0.3949769  0.7498125 -0.09078980  0.4276059
            qsec         vs          am       gear        carb
mpg   0.41868403  0.6640389  0.59983243  0.4802848 -0.55092507
cyl  -0.59124207 -0.8108118 -0.52260705 -0.4926866  0.52698829
disp -0.43369788 -0.7104159 -0.59122704 -0.5555692  0.39497686
hp   -0.70822339 -0.7230967 -0.24320426 -0.1257043  0.74981247
drat  0.09120476  0.4402785  0.71271113  0.6996101 -0.09078980
wt   -0.17471588 -0.5549157 -0.69249526 -0.5832870  0.42760594
qsec  1.00000000  0.7445354 -0.22986086 -0.2126822 -0.65624923
vs    0.74453544  1.0000000  0.16834512  0.2060233 -0.56960714
am   -0.22986086  0.1683451  1.00000000  0.7940588  0.05753435
gear -0.21268223  0.2060233  0.79405876  1.0000000  0.27407284
carb -0.65624923 -0.5696071  0.05753435  0.2740728  1.00000000
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

step3:graph

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 matrix",
       x = "",
       y = ""
       )+
  theme(axis.text.x = element_text(angle = 45,hjust = 1))