# How to Create Kernel Density Plots in R (With Examples)

A kernel density plot is a type of plot that displays the distribution of values in a dataset using one continuous curve.

A kernel density plot is similar to a histogram, but it’s even better at displaying the shape of a distribution since it isn’t affected by the number of bins used in the histogram.

We can use the following methods to create a kernel density plot in R:

Method 1: Create One Kernel Density Plot

```#define kernel density
kd <- density(data)

#create kernel density plot
plot(kd)
```

Method 2: Create a Filled-In Kernel Density Plot

```#define kernel density
kd <- density(data)

#create kernel density plot
plot(kd)

#fill in kernel density plot with specific color
polygon(kd, col='blue', border='black')
```

Method 3: Create Multiple Kernel Density Plots

```#plot first kernel density plot
kd1 <- density(data1)
plot(kd1, col='blue')

#plot second kernel density plot
kd2 <- density(data2)
lines(kd2, col='red')

#plot third kernel density plot
kd3 <- density(data3)
lines(kd3, col='purple')

...```

The following examples show how to use each method in practice.

### Method 1: Create One Kernel Density Plot

The following code shows how to create a kernel density plot for one dataset in R:

```#create data
data <- c(3, 3, 4, 4, 5, 6, 7, 7, 7, 8, 12, 13, 14, 17, 19, 19)

#define kernel density
kd <- density(data)

#create kernel density plot
plot(kd, main='Kernel Density Plot of Data')```

The x-axis shows the values of the dataset and the y-axis shows the relative frequency of each value. The highest points in the plot show where the values occur most often.

### Method 2: Create a Filled-In Kernel Density Plot

The following code shows how to create a kernel density plot with a specific border color and filled-in color:

```#create data
data <- c(3, 3, 4, 4, 5, 6, 7, 7, 7, 8, 12, 13, 14, 17, 19, 19)

#define kernel density
kd <- density(data)

#create kernel density plot
plot(kd)

polygon(kd, col='steelblue', border='black')
```

### Method 3: Create Multiple Kernel Density Plots

The following code shows how to create multiple kernel density plots in one plot in R:

```#create datasets
data1 <- c(3, 3, 4, 4, 5, 6, 7, 7, 7, 8, 12, 13, 14, 17, 19, 19)
data2 <- c(12, 3, 14, 14, 4, 5, 6, 10, 14, 7, 7, 8, 10, 12, 17, 20)

#plot first kernel density plot
kd1 <- density(data1)
plot(kd1, col='blue', lwd=2)

#plot second kernel density plot
kd2 <- density(data2)
lines(kd2, col='red', lwd=2)```

Note that we can use similar syntax to create as many kernel density plots in one chart as we’d like.