The Histogram in R Programming is very useful to visualize the statistical information, that is organized in user specified bins (range, or breaks). Though it looks like Barplot, Histograms in R display data in equal intervals.

In this article we will show you, How to Create a Histogram in R, Remove it Axes, Format its color, adding labels, adding the density curves, and drawing multiple Histograms in R Programming language with example.

## Histogram in R Syntax

The basic syntax to draw the Histogram in R Programming is as shown below

hist(x, col = NULL, main = NULL, xlab = xname, ylab)

and the complex syntax behind this R Histogram is:

hist(x, breaks = "Sturges", freq = NULL, probability = !freq, xlim = range(breaks), ylim = NULL, col = NULL, angle = 45, include.lowest = TRUE, right = TRUE, density = NULL, main = NULL, xlab = xname, ylab, border = NULL, axes = TRUE, plot = TRUE, labels = FALSE, nclass = NULL, warn.unused = TRUE,..)

Before we get into the example, let us the see the data that we are going to use for this Histogram example. * airquality* is the date set provided by the R

## Return Value of a Histogram in R Programming

In general, before we start creating a Histogram, let us see how the data is divided by the histogram.

The Histogram in R will return the frequency (count), density, bin (breaks) values, and type of graph. In this example we will show you, How to get the information of the same

# R Histogram Data airquality return_Value <- hist(airquality$Temp) return_Value

**OUTPUT**

## Create a Histogram in R Programming

In this example we will show you, How to create a Histogram using the * airquality* data set, which is provided by the Studio. If your requirement is to import data from external files then, I suggest you to refer R Read CSV article to understand the csv file import

# Create a R Histogram airquality hist(airquality$Temp)

**OUTPUT**

**ANALYSIS**

* airquality* data set will return the output as a List. So, we are using the

**$**to extract the data from List.

hist(airquality$Temp)

### Assigning names to Histogram in R Programming

In this example we will show you, How to assign names to Histogram, X-Axis, and Y-Axis using **main****, xlab**, and** ylab**

**main:**You can change, or provide the Title for your Histogram.**xlab:**Please specify the label for the X-Axis**ylab:**Please specify the label for the Y-Axis**las:**It is used to change the Y axis values direction

# R Histogram Example - Changing Axis Names airquality hist(airquality$Temp, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Frequency", las = 1 )

**OUTPUT**

### Change Colors of a Histogram in R

In this example we will show you, How to change the Histogram color using * col* argument

**col:**Please specify the color you want to use for your Histogram. Typein your console to get the list of colors available in R programming**colors()**

# R Histogram Example - Changing Colors airquality hist(airquality$Temp, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Frequency", las = 1, col = c("skyblue", "chocolate2") )

From the above code snippet you can observe that, we used two colors for the col argument. It means, those two colors will be repeated until the end of bars.

**OUTPUT**

### Remove Axis and Adding labels to Histogram in R

In this example we will show you, How to remove the X-Axis, Y-Axis, and how to assign labels to each bar in histogram using * axes*,

*, and*

**ann***argument.*

**labels****axes:**It is a Boolean argument. If it is TRUE, axis is drawn.**labels:**It is a Boolean argument. If it is TRUE, Histogram will return the value of each bar on top it.**ann:**It is a Boolean argument. If it is FALSE, Histogram will remove the annotations from the plot area, which includes Histogram name, Axis Names.

# R Histogram Example - Removing Axis Labels airquality return_Value <- hist(airquality$Temp) return_Value hist(airquality$Temp, axes = FALSE, ann = FALSE, labels = TRUE, ylim = c(0, 35), col = c("skyblue", "chocolate2") )

**OUTPUT**

### Change Axis limits of a Histogram

In this example we will show you, How to change the default axis values, and also changing the bar density using * density* argument of R histogram

**xlim:**This argument can help you to specify the limits for the X-Axis**ylim:**This argument may help you to specify the Y-Axis limits. In this example, We are changing the default y-axis values (0, 35) to (0, 40)**density:**Please specify the shading lines density (in lines per inch). By default it is NULL, means no shading lines.

**R CODE**

# R Histogram Example - Changing Axis Values airquality return_Value <- hist(airquality$Temp) return_Value hist(airquality$Temp, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Frequency", las = 1, col = c("skyblue", "chocolate2"), xlim = c(55, 100), ylim = c(0, 40), density = 80 )

**OUTPUT**

### Changing Bins of a Histogram

In this example we will show you, How to change the Bin size of R histogram using * breaks* argument

- You can use a Vector of values that specify the break points between histogram cells.
- You can use a Number that specify the number of cells a histogram has to return. For example, breaks = 20 means, 20 bars will be returned.
- You can use a function that returns a Vector of break points.

# R Histogram Example - Changing Bins airquality return_Value <- hist(airquality$Temp) return_Value hist(airquality$Temp, breaks = 20, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Frequency", las = 1, col = c("skyblue", "chocolate2"), labels = TRUE, ylim = c(0, 25) )

**OUTPUT**

## Create a R Histogram with Density

Frequency will count and give us the number of data points per bin. In real-time we are more interested in density than the frequency based histograms because, density can give the probability densities.

In this example we will show you, How to create a Histogram in R against the Density and to achieve the same, we have set the * freq* argument to FALSE.

# R Histogram Example - Density Values airquality return_Value <- hist(airquality$Temp) return_Value hist(airquality$Temp, freq = FALSE, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Density", las = 1, col = c("skyblue", "chocolate2") )

**OUTPUT**

### Adding Density Curve to Histogram

In this example we will show you, How to add the density curve to Histogram in R programming using * lines* function.

# R Histogram Example - Add Density Curve airquality hist(airquality$Temp, freq = FALSE, main = "Temperature Histogram", xlab = "Temperature", ylab = "Temperature Density", las = 1, col = c("skyblue", "chocolate2") ) lines(density(airquality$Temp), lwd = 4, col = "red")

**OUTPUT**

**ANALYSIS**

Following statement will draw a density curve

lines(density(airquality$Temp), lwd = 4, col = "red")

**TIP:** lwd argument is used to change the width of the line

## Add Multiple Histograms in R

In this example we will show you, How to add multiple Histogram to plot region.

# R Histogram Example - Multiple Histograms airquality # Drawing Histogram for all the temperature values, where Month Number = 7 hist(airquality$Temp[airquality$Month == 7], main = "Multiple Histograms", xlab = "Temperature", ylab = "Temperature Frequency", las = 1, breaks = 20, col = "skyblue", labels = T ) # Drawing Histogram for all the temperatures, where Month Number = 8 hist(airquality$Temp[airquality$Month == 8], add = TRUE, col = "chocolate2", breaks = 20, labels = T )

**OUTPUT**

## Creating R Histogram using CSV File

In this example we will show you, How to create a Histogram in R using the external data. For this, we are importing data from the csv file using read.csv function. please refer R Read CSV article.

# R Histogram Example - CSV File employee <- read.csv("Products.csv", TRUE, sep = ",", na.strings = TRUE) employee$SalesAmount hist(employee$SalesAmount, main = "Sales Histogram", xlab = "Sale Amount", ylab = "Sales Frequency", las = 1, col = "skyblue" )

Above code snippet will draw the histogram in R for the Sales Amount

**OUTPUT**