R pie chart is created using the **pie() **function which takes positive numbers as a vector input. The additional parameters are used to control appearance of pie charts in R are labels, color, title etc.

**Syntax R Pie chart**

The basic syntax for creating a pie chart using the R is:

pie(x, labels, radius, main, col, clockwise)

Following is the description of the parameters used:

**x**is a vector containing the numeric values used in the pie chart.**labels**is used to give description to the slices.**radius**indicates the radius of the circle of the pie chart.(value between -1 and +1).**main**indicates the title of the chart.**col**indicates the color palette.**clockwise**is a logical value indicating if the slices are drawn clockwise or anti clockwise.

__A simple Pie chart in R: __

__A simple Pie chart in R:__

A very simple pie chart is created using just the input vector and labels. The below script will create and save the pie chart

# Create data for the graph. x <- c(32, 12, 30, 53) labels <- c("California", "Paris", "Moscow", "Mumbai") # Plot the chart pie(x,labels)

When we execute the above code, it produces the following simple pie chart

Now lets Add the Title and change the colour of the pie chart. Lets name title as “city_pie_chart” and colour with four rainbow colours as follows

pie(x,labels,main="city_pie_chart",col=rainbow(4))

so the output will be

__R Pie chart with labels and respective percentage:__

Now lets construct a pie chart with labels followed by Percentages. Look at the below example

x <- c(32, 12, 30, 45) labels <- c("California", "Paris", "Moscow", "Mumbai") pct <- round(x/sum(x)*100) lbls <- paste(labels, pct) # add percents to labels lbls <- paste(lbls,"%",sep="") # ad % to labels pie(x,labels = lbls, col=rainbow(length(lbls)),main="city_pie_chart")

**line no:3** calculates the percentages and stores it in variable pct

**line no:4** concatenates labels and pct values and stores it in variable lbls

**line no:5** concatenates lbls and % symbol with null separator andstores it in variable lbls

**line no:6** lbls is passed as input to the label parameter in pie() function

which produces the following output.

__R Pie chart with Legends__

now lets add legend to the above pie chart it is quite simple and can be done with the function legend() which has to be run along with the pie() function

pie(x,labels = lbls, col=rainbow(length(lbls)),main="city_pie_chart") legend("topright", c("California", "Paris", "Moscow", "Mumbai"), cex=0.8,fill=rainbow(length(x)))

which produces the following output

__3D Pie Chart in R:__

__3D Pie Chart in R:__

The package **plotrix **has a function called **pie3D() **that is used for plotting a 3D Pie chart in R.

library(plotrix) pie3D(x,labels=lbls,explode=0.1,main="city_pie_chart")

explode is a parameter used to increase or decrease the gap of split in slices. Above code produces the following output