Histograms in R language

A histogram contains 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 similar to a vertical bar graph.

R creates histogram 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

Approach: In order to create Histogram chart:

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

Example:

# 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

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

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

Example

# 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()

Approach: To create histogram return value chart:

# 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: When we execute the above code, it shows the following result-

Histogram using non-uniform width

Approach: creating different width histogram chart:

By using above parameters, we created histogram using non-uniform width.

Example

# 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:

My Personal Notes

Creating a simple Histogram

Range of X and Y values

Using histogram return values for labels using text()

Histogram using non-uniform width

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