# Create Raster Plot from Data Frame in R (2 Examples)

On this page you’ll learn how to convert a data frame to a raster plot in R.

The page is structured as follows:

Here’s the step-by-step process:

## Example 1: Convert Data Frame to Raster

Example 1 shows a simplified example on how to draw a raster graphic from a data frame in R.

First, we have to specify the number of rows and columns of our raster:

`n1 <- 2 # Specify number of raster rows & columns`

Furthermore, we have to set a random seed to make our examples reproducible:

`set.seed(3287253) # Set seed for reproducibility`

Next, we can create a data frame for our raster plot:

```data1 <- data.frame(x = rep(1:n1, each = n1), # Create data frame for raster y = rep(1:n1, n1), value = runif(n1^2)) data1 # Print data frame``` As shown in Table 1, we have created a new data frame containing four rows and three columns. The first two columns are the coordinates and the third column contains the values that correspond to each coordinate.

Next, we have to install and load the raster package, to be able to use the functions that are contained in the package:

```install.packages("raster") # Install & load raster package library("raster")```

Now, we can use the rasterFromXYZ function of the raster package to convert our data frame to a raster object:

```data_raster1 <- rasterFromXYZ(data1) # Convert data frame to raster object data_raster1 # Print raster object # class : RasterLayer # dimensions : 2, 2, 4 (nrow, ncol, ncell) # resolution : 1, 1 (x, y) # extent : 0.5, 2.5, 0.5, 2.5 (xmin, xmax, ymin, ymax) # crs : NA # source : memory # names : value # values : 0.1371583, 0.9959187 (min, max)```

We can now apply the plot function to our raster object to draw a raster graphic:

`plot(data_raster1) # Draw raster` In Figure 1 you can see that we have plotted a very simple raster by running the previous syntax.

The next example will show how to make the raster more complex.

## Example 2: Creating Raster Plot of More Complex Data

In Example 2, I’ll explain how to use our code to create more complex raster graphs in R.

For this, we simply have to increase the number of rows and columns of our raster plot. In this case, we are using the number 30:

`n2 <- 30 # Specify number of raster rows & columns`

The following code is very similar to Example 1. First we have to create a data frame

```data2 <- data.frame(x = rep(1:n2, each = n2), # Create data frame for raster y = rep(1:n2, n2), value = runif(n2^2)) head(data2) # Print head of data frame``` Table 2 shows the first six rows of our data frame.

Next, we can apply the rasterFromXYZ function to transform our data frame to a raster object…

```data_raster2 <- rasterFromXYZ(data2) # Convert data frame to raster object data_raster2 # Print raster object # class : RasterLayer # dimensions : 30, 30, 900 (nrow, ncol, ncell) # resolution : 1, 1 (x, y) # extent : 0.5, 30.5, 0.5, 30.5 (xmin, xmax, ymin, ymax) # crs : NA # source : memory # names : value # values : 0.0001614387, 0.9979389 (min, max)```

…and finally, we can draw our raster:

`plot(data_raster2) # Draw raster` The output of the previous syntax is shown in Figure 2: A more complex raster graphic.

Obviously, this raster plot doesn’t make much sense. However, you might change the values of the coordinates to create more useful raster plots in R.

## Video, Further Resources & Summary

Have a look at the following video on my YouTube channel. I’m explaining the R codes of this tutorial in the video.

The YouTube video will be added soon.

Furthermore, you may read some of the related tutorials on this website:

This tutorial has demonstrated how to draw a raster plot based on a data frame in R programming. In case you have further comments or questions, don’t hesitate to let me know in the comments.

Subscribe to the Statistics Globe Newsletter

Get regular updates on the latest tutorials, offers & news at Statistics Globe.
I hate spam & you may opt out anytime: Privacy Policy.