# How to create a heat map on R programming?

How to create a heat map on R programming? Heat maps are a graphical representation of data that uses color coding to show the values of a matrix. They are useful for visualizing large amounts of data and identifying patterns and trends. This article will show you how to create a heat map in R programming. To create a heat map in R, we will use the heatmap() function, which is part of the base R package. We will also use the scale() function to normalize the data so that the colors represent the relative values of the matrix.

Here are the steps to create a heat map in R:

The data for your heat map should be in a matrix format, with rows and columns representing variables and the values representing the observations. Here is an example of a matrix:

data <- matrix(c(10, 20, 30, 40, 50, 60, 70, 80, 90), nrow = 3, ncol = 3)

Step 2: Normalize the data

We will use the scale() function to normalize the data so that the colors represent the relative values of the matrix. This is done by subtracting the mean and dividing by the standard deviation of each row or column:

scaled_data <- scale(data, center = TRUE, scale = TRUE)

Step 3: Create the heat map

To create the heat map, we will use the heatmap() function. Here is the code:

heatmap(scaled_data, col = rev(heat.colors(10)), margins = c(5, 10))

The scaled_data argument is the matrix of normalized data. The col argument specifies the color palette to use. In this case, we are using the heat.colors() function to generate a palette of 10 colors, which we reverse with the rev() function so that higher values are darker. The margins argument specifies the size of the margins around the heat map.

Step 4: Add labels to the heat map

To add labels to the heat map, we can use the xlab, ylab, and main arguments. Here is an example:

heatmap(scaled_data, col = rev(heat.colors(10)), margins = c(5, 10),
xlab = "Columns", ylab = "Rows", main = "Heat Map Example")

The xlab argument specifies the label for the x-axis, the ylab argument specifies the label for the y-axis, and the main argument specifies the main title of the heat map.

Step 5: Customize the heat map

There are many ways to customize the heat map in R. For example, you can change the font size and color of the labels, adjust the size of the heat map, and add a color scale legend. Here is an example of how to change the font size and color of the labels:

heatmap(scaled_data, col = rev(heat.colors(10)), margins = c(5, 10),         xlab = "Columns", ylab = "Rows", main = "Heat Map Example",         cex.axis = 1.5, col.axis = "white")

The cex.axis argument specifies the font size of the axis labels, and the col.axis argument specifies the color of the axis labels.

### 56 thoughts on “How to create a heat map on R programming?”

1. What’s Taking place i am new to this, I stumbled upon this I have found It absolutely helpful and it has helped me out loads.
I hope to give a contribution & assist other users like its aided
me. Good job.

2. Pingback: sig sauer p365
3. I really like what you guys are usually up too. Such clever work and coverage! Keep up the awesome works guys I’ve included you guys to my personal blogroll.

4. Pingback: lorazepam 2mg
5. I simply couldn’t go away your website prior to suggesting that I actually loved the standard info an individual supply for your guests? Is going to be again incessantly to check out new posts.

7. Wonderful web site. Plenty of helpful info here. I am sending it to some pals ans also sharing in delicious. And obviously, thanks on your effort!

8. I have read several excellent stuff here. Definitely value bookmarking for revisiting. I surprise how much attempt you place to make the sort of fantastic informative web site.

9. I cling on to listening to the rumor speak about receiving free online grant applications so I have been looking around for the most excellent site to get one. Could you advise me please, where could i get some?

10. Real clear internet site, regards for this post.

11. Pingback: bonanza178
12. Do you mind if I quote a few of your posts as long as I provide
credit and sources back to your blog? My blog site is in the very same niche as yours and my users would genuinely benefit from a lot of the information you present
here. Please let me know if this alright with you. Thank you!

13. What’s Taking place i am new to this, I stumbled upon this I have discovered It absolutely useful and it has helped me out loads. I hope to give a contribution & help other customers like its helped me. Good job.

14. of course like your web site but you need to test the spelling on several of your posts. Many of them are rife with spelling issues and I to find it very bothersome to inform the truth nevertheless I will surely come back again.

15. Hey There. I found your blog using msn. This is an extremely well written article. I will be sure to bookmark it and return to read more of your useful information. Thanks for the post. I will definitely return.

16. Hi, i read your blog occasionally and i own a similar one and i was just wondering
if you get a lot of spam remarks? If so how do you protect against it,
any plugin or anything you can suggest? I get so much lately it’s driving me mad so any assistance is very much appreciated.

17. Pingback: slot online
18. Hi there! This post couldn’t be written any better! Reading through this post reminds me of my previous room mate! He always kept talking about this. I will forward this article to him. Pretty sure he will have a good read. Thank you for sharing!

19. I see something really interesting about your site so I saved to fav.