Histograms in R language

A histogram contains a rectangular area to display the statistical information which is proportional to the frequency of a variable and its width in successive numerical intervals. A graphical representation that manages a group of data points into different specified ranges. It has a special feature that shows no gaps between the bars and is similar to a vertical bar graph.

We can create histograms in R Programming Language using the hist() function.

Syntax:

hist(v, main, xlab, xlim, ylim, breaks, col, border)

Parameters: 

• v: A vector containing numerical values for the histogram.
• main: The title of the chart.
• col: The color of the bars.
• xlab: The label for the x-axis.
• border: The border color of each bar.
• xlim: The range of values for the x-axis.
• ylim: The range of values for the y-axis.
• breaks: The width of each bar.

1. Creating a simple Histogram in R

Creating a simple histogram chart by using the above parameter. This vector v is plot using hist().

Example: 

v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19, 27, 39)

hist(v, xlab = "No.of Articles ",
     col = "green", border = "black")

Output:

1.1 Range of X and Y values

To describe the range of values we need to do the following steps: 

1. We can use the xlim and ylim parameters in X-axis and Y-axis.
2. Take all parameters which are required to make a histogram chart.

Example 

v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19, 27, 39)

hist(v, xlab = "No.of Articles", col = "green",
    border = "black", xlim = c(0, 50),
    ylim = c(0, 5), breaks = 5)    

Output: 

2. Using histogram return values for labels using text()

To create a histogram return value chart.

v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19, 27, 39, 120, 40, 70, 90)

m<-hist(v, xlab = "Weight", ylab ="Frequency",
        col = "darkmagenta", border = "pink", 
        breaks = 5)

text(m$mids, m$counts, labels = m$counts, 
     adj = c(0.5, -0.5))    

Output:

3. Histogram using non-uniform width

Creating different width histogram charts, by using the above parameters, we created a histogram using non-uniform width.

Example 

v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19, 27, 39, 120, 40, 70, 90)
    
hist(v, xlab = "Weight", ylab ="Frequency",
     xlim = c(50, 100),
    col = "darkmagenta", border = "pink",
    breaks = c(5, 55, 60, 70, 75,
               80, 100, 140))

Output: