R - Pie Charts
In R the pie chart is created using the pie() function which takes positive numbers as a vector input.
pie(x, labels, radius, main, col, clockwise)
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 anticlockwise.
Example
We can add slice percentage and a chart legend by creating additional chart variables.
Code-
# Create data for the graph.
x <- c(21, 62, 10,53)
labels <- c("London","NewYork","Singapore","Mumbai")
piepercent<- round(100*x/sum(x), 1)
# Give the chart file a name.
png(file = "city_percentage_legends.jpg")
# Plot the chart.
pie(x, labels = piepercent, main = "City pie chart",col = rainbow(length(x)))
legend("topright", c("London","New York","Singapore","Mumbai"), cex = 0.8,
fill = rainbow(length(x)))
# Save the file.
dev.off()
When we execute the above code, it produces the following result −
3D Pie Chart
A pie chart with 3 dimensions can be drawn using additional packages. The package plotrix has a function called pie3D() that is used for this.
Code-
# Get the library.
library(plotrix)
# Create data for the graph.
x <- c(21, 62, 10,53)
lbl <- c("London","NewYork","Singapore","Mumbai")
# Give the chart file a name.
png(file = "3d_pie_chart.jpg")
# Plot the chart.
pie3D(x,labels = lbl,explode = 0.1, main = "Pie Chart of Countries ")
# Save the file.
dev.off()
When we execute the above code, it produces the following result −
R - Bar Charts
R uses the function barplot() to create bar charts.
Syntax-
The basic syntax to create a bar-chart in R is
barplot(H, xlab, ylab, main, names.arg, col)
Following is the description of the parameters used −
H is a vector or matrix containing numeric values used in bar chart.
xlab is the label for x axis.
ylab is the label for y axis.
main is the title of the bar chart.
names.arg is a vector of names appearing under each bar.
col is used to give colors to the bars in the graph.
Group Bar Chart and Stacked Bar Chart
We can create bar chart with groups of bars and stacks in each bar by using a matrix as input values.
More than two variables are represented as a matrix which is used to create the group bar chart and stacked bar chart.
Code-
# Create the input vectors.
colors <- c("green","orange","brown")
months <- c("Mar","Apr","May","Jun","Jul")
regions <- c("East","West","North")
# Create the matrix of the values.
Values <- matrix(c(2,9,3,11,9,4,8,7,3,12,5,2,8,10,11),nrow = 3,ncol = 5,byrow = TRUE)
# Give the chart file a name.
png(file = "barchart_stacked.png")
# Create the bar chart.
barplot(Values,main = "total revenue",names.arg = months,xlab = "month",ylab = "revenue",
col = colors)
# Add the legend to the chart.
legend("topleft", regions, cex = 1.3, fill = colors)
R - Line Graphs
A line chart is a graph that connects a series of points by drawing line segments between them. These points are ordered in one of their coordinate (usually the x-coordinate) value. Line charts are usually used in identifying the trends in data.
The plot() function in R is used to create the line graph.
Syntax-
The basic syntax to create a line chart in R is −
plot(v,type,col,xlab,ylab)
Following is the description of the parameters used −
v is a vector containing the numeric values.
type takes the value "p" to draw only the points, "l" to draw only the lines and "o" to draw both points and lines.
xlab is the label for x axis.
ylab is the label for y axis.
main is the Title of the chart.
col is used to give colors to both the points and lines.
Example
Multiple Lines in a Line Chart
More than one line can be drawn on the same chart by using the lines()function.
After the first line is plotted, the lines() function can use an additional vector as input to draw the second line in the chart,
Code-
# Create the data for the chart.
v <- c(7,12,28,3,41)
t <- c(14,7,6,19,3)
# Give the chart file a name.
png(file = "line_chart_2_lines.jpg")
# Plot the bar chart.
plot(v,type = "o",col = "red", xlab = "Month", ylab = "Rain fall",
main = "Rain fall chart")
lines(t, type = "o", col = "blue")
# Save the file.
dev.off()
When we execute the above code, it produces the following result –
