What are histograms in R?
A histogram shows the frequencies of values of a variable bucketed into ranges. A histogram is alike to a bar chart but the deviation is it groups the values into continuous ranges. Every bar in the histogram represents the height of the number of values present in that range.
R generates histograms using the hist() method. This function uses a vector as an input and takes some further parameters (for additional attributes) to plot histograms.
Syntax
The basic syntax to generate a histogram using R is as follows:
hist(v, main, xlab, xlim, ylim, breaks, col, border)
Parameters
v: Vector that contains arithmetical values used in the histogram.main: Indicates the title of a chart.col: Taken to set the color of chat bars.xlab: Used to give brief information of x-axis.xab: Used to give a brief detail of x-axis.xlim: Used to define the range of values on the x-axis.ylim: Taken to define the range of values on the y-axis.Breaks: Used to show the width of each bar.border: Used to set the border color of all bars.
Simple histogram plot
A simple histogram is generated by using the input vector, label, col, and border parameters. The information given below is provided to create and save the histogram in the current R working directory.
# First create data for graph.v <- c(9,13,21,8,36,22,12,41,31,33,19)# Make histogramhist(v,xlab = "weight",col = "yellow",border = "blue")
Bins and breaks
To change the bin width you can specify Breaks as an argument including the breakpoints you want to have. You can do this by using c() method: Vector c(100,200,300,500,700) is being specified.
hist(x, breaks=c(100,200, 300, 500, 700))
Range of x and y values
To set out the range of values allowed in the X-axis and Y-axis, we take the xlim and ylim parameters. The width of all bars can be selected by using breaks.
# Generate data for the graphv<- c(9,13,21,8,36,22,12,41,31,33,19)# Make histogram.hist(v,xlab = "Weight",col = "green",border = "red",xlim = c(4,6),ylim = c(1,2),breaks = 5)
