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 which shows no gaps between the bars and is similar to a vertical bar graph.

R – Histograms

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

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

Parameters:

• v: This parameter contains numerical values used in histogram.
• main: This parameter main is the title of the chart.
• col: This parameter is used to set color of the bars.
• xlab: This parameter is the label for horizontal axis.
• border: This parameter is used to set border color of each bar.
• xlim: This parameter is used for plotting values of x-axis.
• ylim: This parameter is used for plotting values of y-axis.
• breaks: This parameter is used as width of each bar.

Creating a simple Histogram in R

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

Example:

R

# Create data for the graph.
v <- c(19, 23, 11, 5, 16, 21, 32,
       14, 19, 27, 39)

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

Output:

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 parameter in X-axis and Y-axis.
2. Take all parameters which are required to make histogram chart.

Example

R

# Create data for the graph.
v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19, 27, 39)


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

Output:

Using histogram return values for labels using text()

To create a histogram return value chart.

R

# Creating data for the graph.
v <- c(19, 23, 11, 5, 16, 21, 32, 14, 19,
       27, 39, 120, 40, 70, 90)

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

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

Output:

Histogram using non-uniform width

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

Example

R

# Creating data for the graph.
v <- c(19, 23, 11, 5, 16, 21, 32, 14,
       19, 27, 39, 120, 40, 70, 90)

# Creating the histogram.
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: