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:
