Get regular updates on the latest tutorials, offers & news at Statistics Globe. The legend can be positioned outside of the plot box using the theme () function as follows. #> 3 5.18 Control Note that I illustrated how to create a legend based on a scatterplot. To put a legend inside the plot, you supply legend.position as coordinates on a relative scale that runs from [0,0] in the lower left to [1,1] in the upper right. y = rnorm(100), Because group, the variable in the legend, is mapped to the color fill, it is necessary to use scale_fill_xxx, where xxx is a method of mapping each factor level of group to different colors. Instead of scale_fill_discrete, you may need to use a different scale, such as scale_fill_manual, scale_colour_hue, scale_colour_manual, scale_shape_discrete, scale_linetype_discrete, and so on. Legends in R How to modify the legend in R graphs. Otherwise there will be two two separate legends. #> 5 4.50 Control Have a look at the following R syntax: ggplot(data, aes(x, y, col = group)) + # ggplot with legend In this case the argument guide is used as follow : Remove the legend for a specific aesthetic. guide_colourbar() or guide_legend()) specifying additional arguments. # 0.3344750 0.5165524 5 colour maps to the colors of lines and points, while fill maps to the color of area fills. logical. library("ggplot2") # Load ggplot2 library. ... To improve the readability of plot, one may add title, label axes, and provide legend. ... # position of guides # Set order for multiple guides ggplot … shape maps to the shapes of points. You might want to add the plot’s … However, our plot is not showing a legend for these colors. This is an introductory textbook that focuses on how to use R to do technical analysis. The axis text can be rotated by changing the angle. #> 6 4.61 Control, # Position legend in graph, where x,y is 0,0 (bottom left) to 1,1 (top right), # Set the "anchoring point" of the legend (bottom-left is 0,0; top-right is 1,1) group = factor(round(runif(100, 1, 5)))) Required fields are marked *. The first way is to tell the scale to use have a different title and labels. This is in many instances a nice solution. alignment of legend labels (number from 0 (left) to 1 (right)) legend.title This post explains how to add a legend to a chart made with base R, using the legend() function. Note that an equivalent page exist concerning legends with ggplot2. Note that we colored our plot by specifying the col argument within the geom_point function. # Rename the column and the values in the factor, #> weight Experimental Condition The default is to use a different hue on the color wheel for each factor level, but it is also possible to manually specify the colors for each level. I hate spam & you may opt out anytime: Privacy Policy. 10% of the Fortune 500 uses Dash Enterprise to … geom_point(). size of legend keys (unit); key background height & width inherit from legend.key.size or can be specified separately. By default, ggplot2 uses the variable names present in the dataframe as legend titles. # reversed order legend p + guides (col = guide_legend (reverse = TRUE)) Contents ggplot2 is a part of the tidyverse , an ecosystem of packages designed with common APIs and a shared philosophy. In addition, I can recommend to have a look at some of the related posts of this homepage. require(["mojo/signup-forms/Loader"], function(L) { L.start({"baseUrl":"mc.us18.list-manage.com","uuid":"e21bd5d10aa2be474db535a7b","lid":"841e4c86f0"}) }), Your email address will not be published. There are two ways of changing the legend title and labels. Subscribe to my free statistics newsletter. If you accept this notice, your choice will be saved and the page will refresh. Get regular updates on the latest tutorials, offers & news at Statistics Globe. They take the form scale_xxx_yyy. There are many kinds of scales. Start with an example graph with the default options: Use guides(fill=FALSE), replacing fill with the desired aesthetic. As you can see based on Figure 2, we just added a legend to our plot, by moving the col argument within the aes function in the first line of the code. We’ll show examples of how to move the legend to the bottom or to the top side of the plot. Also note the use of backticks instead of quotes. The Labels. 1. vjust, controls the vertical spacing between title (or label) and plot. The desired number of column of legends. If you use a line graph, you will probably need to use scale_colour_xxx and/or scale_shape_xxx instead of scale_fill_xxx. Now, we can create a scatterplot with the ggplot2 package as follows: ggplot(data, aes(x, y)) + # ggplot without legend There is not a built-in way to remove the slashes, but it is possible to cover them up. In this post I’ll first introduce # x y group https://github.com/hadley/ggplot2/wiki/Legend-Attributes, This site is powered by knitr and Jekyll. #> 4 6.11 Control # -2.0441421 2.6587881 1 The R code below removes the legend for the aesthetics color and size : p+guides(color = FALSE, size = FALSE) Removing a particular legend can be done also when using the functions scale_xx. Note that the numeric position below is relative to the entire area, including titles and labels, not just the plotting area. Below, I have changed the size, color, face and line-height. I hate spam & you may opt out anytime: Privacy Policy. Here we specify legend.position = c(0.87,0.25) to place the legend … #> 2 5.58 Control logical. A list containing the mapping between scale and guide. In general, if you want to map an aesthetic to a variable and get a legend in ggplot2 you do it inside aes().If you want to set an aesthetic to a constant value, like making all your points purple, you do it outside aes().. ggplot (data, aes (x, y)) + # Specifying legend in geom geom_point (aes (col = group)) The output is the same as in Example 2. At this point, you have learned basically all things you need to know in order to remove legends in R ggplots. # 0.9588898 -0.8429466 2 You’ll will also learn how to put the legend … For further information, see: Here, you can learn how to modify colors of a ggplot2 plot manually. {ggplot2} package (which needs to be installed and loaded beforehand) The {graphics} package comes with a large choice of plots (such as plot, hist, barplot, boxplot, pie, mosaicplot, etc.) Alter Legend position of an R ggplot2 Boxplot. It provides beautiful, hassle-free plots that take care of minute details like drawing legends and representing them. The following is all the available draw_key_* functions in ggplot2. Of cause, this kind of code could also be applied to other aesthetics as well as to other kinds of plots (histogram, barchart, QQplot etc.). The plots can be created iteratively and edited later. Position options include “top”, “bottom”, “left” and “right”. This changes the order of items to trt1, ctrl, trt2:Depending on how the colors are specified, you may have to use a different scale, such as scale_fill_manual, scale_colour_hue, scale_colour_manual, scale_shape_discrete, scale_linetype_discrete, and so on. ncol. Note that I illustrated how to create a legend based on a scatterplot. If we want to add a legend to our ggplot2 plot, we need to specify the colors within the aes function (i.e. This makes ggplot2 powerful. # A hack to hide the slashes: first graph the bars with no outline and add the legend, We’ll use a different data set for the line graphs here because the PlantGrowth data set does not work well with a line graph. # You can also modify the scale directly: # Here's what happens if you just specify colour, # Copy data into new data frame Load required packages and set the theme function theme_minimal() as the default theme: The guide can either be a string (i.e. See details and examples. Figure 1 shows the plot we creates with the previous R code. How to create ggplot labels in R Annotate ggplot with text labels using built-in functions and create non-overlapping labels with the ggrepel package. We can move the ggplot2 legend inside the plot, when there is empty space inside. So if you use color, shape or alpha, a legend will be available. If we want to draw a plot with the ggplot2 package, we need to install and load the package: install.packages("ggplot2") # Install ggplot2 Notice that the dark gray color in dotplot and polygon is a result of a unspecified fill aesthetic. Save the legend of the plot p1 as an external graphical element (called a “grob” in Grid terminology) Remove the legends from all plots; Draw all the plots with only one legend in the right panel; To save the legend of a ggplot, the helper function below can be used : ggplot2 is an R package for producing statistical, or data, graphics. #> 1 4.17 Control Your email address will not be published. The following code shows how to use the legend.key.size argument to make the keys of the legend larger: ggplot (df, aes(fill=position, y=points, x=team)) + geom_bar (position='dodge', stat='identity') + theme (legend.key.size = unit (2, 'cm')) In summary: On this page, I showed how to add a legend to a ggplot2 graphic in the R programming language. ggplot2 default legend title. This is useful for making the legend more readable or for creating certain types of combined legends. ggplot2 is an R package which is designed especially for data visualization and providing best exploratory data analysis. geom_point(col = data$group). Remove a legend for a particular aesthetic. Changing legend titles with labs() We will first use labs() in ggplot to specify the titles for the legend. Code to generate these figures can be found at the end of this post. geom_point): ggplot(data, aes(x, y)) + # Specifying legend in geom By accepting you will be accessing content from YouTube, a service provided by an external third party. Simple Scatter Plot with Legend How to Move Legend to inside plot in ggplot2? guide_legend() guide_legend () allows the user to change only the legend appearance without affecting the rest of the plot. Here is an example based on the mtcars dataset. Another alternative is that you specify the col argument within the aesthetics of the geom function (i.e. By default, ggplot position the legend at the right side of a Boxplot in R. In this example, we change the legend position from right to the top. You can also remove all the legends in a graph, using theme. Reposition legend onto plotting panel ggplot2 by default places the legend in the margin of the entire plot. The second way is to change data frame so that the factor has the desired form. They are necessary because of the spaces in the variable name. 1.1 Welcome to ggplot2. Our third aesthetic happens to be properly labeled, and thus, the legend ends up … # then graph the bars again with outline, but with a blank legend. Legends can also be placed inside the plot box using x/y coordinates, where (0,0) is the lower left corner and (1,1) is the upper right corner. 2. hjust, contr… If you make bar graphs with an outline (by setting colour=”black”), it will draw a slash through the colors in the legend. Default legend with ggplot2 By default, ggplot2 will automatically build a legend on your chart as soon as a shape feature is mapped to a variable in aes () part of the ggplot () call. The ggtext package aims to simplify styling text on your visualizations. legend.text. Nine examples of how to move, color, and hide the legend. The override.aes argument in guide_legend () allows the user to change only the legend appearance without affecting the rest of the plot. Showcase. See Axes (ggplot2) for information on how to modify the axis labels. ggplot2 - Introduction. the aesthetics) of our ggplot2 code. Now that you have drawn the main parts of the graph. In the default setting of ggplot2, the legend is placed on the right of the plot. The legend title “Experimental Condtion” is long and it might look better if it were broken into two lines, but this doesn’t work very well with this method, since you would have to put a newline character in the name of the column. The other method, with scales, is generally a better way to do this. The legend can be a guide for fill, colour, linetype, shape, or other aesthetics. Creation of Example Data & Setting Up ggplot2 Package, how to modify colors of a ggplot2 plot manually, Remove Legend Title from ggplot2 Plot in R, Add Common Legend to Combined ggplot2 Plot, Set ggplot2 Axis Limit Only on One Side in R (Example), Order Bars of ggplot2 Barchart in R (4 Examples), Draw ggplot2 Plot with Lines and Points in R (Example), Change Display Order of ggplot2 Plot Legend in R (Example). Our example data contains three columns and 100 rows. Therefore, it can be modified using the theme() function. The desired number of rows of legends. Related Book GGPlot2 Essentials for Great Data Visualization in R. Prerequisites. Add title by using ggtitle() ggplot (df) + aes (x,y) + geom_point + ggtitle ("title") I need to add a simple legend for the colors. legend item labels (element_text(); inherits from text) legend.text.align. data <- data.frame(x = rnorm(100), # Create data Please accept YouTube cookies to play this video. Plot and axis titles and the axis text are part of the plot’s theme. We can specify the location of legend using ggplot2 function theme(). © Copyright Statistics Globe – Legal Notice & Privacy Policy. The first and second column contain the values that we will draw in a scatterplot later on and the third column is the grouping variable that we need to assign colors and to add a legend to our plot. A list specifying aesthetic parameters of legend key. Note that this didn’t change the x axis labels. I have a line plot with three continuous variables. We can change multiple legend titles in at least two ways. The table of content is structured as follows: In the examples of this tutorial, we’ll use the following data frame as basement: set.seed(9649) # Set seed we use the breaks argument to ensure that the labels in legend represent certain midpoints (125, 200, 275) of the mapped variable. Of case we could apply the same R codes to other types of plots such as histograms, barcharts, line plots and so on. Now, since we have a plot and it comes with a legend by default, any modification we would love to make on the legends can be subsequently added on to our initial plot (see: Article 1 on how ggplot2 works).