You'll usually want to use legend.justification, too — this tells ggplot which part of the legend box should align with the coordinates. You’ll will also learn how to put the legend … 10% of the Fortune 500 uses Dash Enterprise to … I have a line plot with three continuous variables. Add title by using ggtitle() ggplot (df) + aes (x,y) + geom_point + ggtitle ("title") Now that you have drawn the main parts of the graph. So if you use color, shape or alpha, a legend will be available. The desired number of column of legends. We can specify the location of legend using ggplot2 function theme(). Note that the numeric position below is relative to the entire area, including titles and labels, not just the plotting area. and additional related features (e.g., abline, lines, legend, mtext, rect, etc.). ncol. The desired number of rows of legends. ggplot2 is an R package for producing statistical, or data, graphics. Showcase. If you accept this notice, your choice will be saved and the page will refresh. In addition, I can recommend to have a look at some of the related posts of this homepage. The legend can be positioned outside of the plot box using the theme () function as follows. ggplot2 Legends: Title. The default legend direction is vertical but it can be changed to horizontal as well and for this purpose we can use legend.direction argument of theme function of ggplot2 package. There are two ways of changing the legend title and labels. 1.1 Welcome to ggplot2. In this post I’ll first introduce 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. 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). ggplot2 - Introduction. © Copyright Statistics Globe – Legal Notice & Privacy Policy. guide_colourbar() or guide_legend()) specifying additional arguments. y = rnorm(100), ... 3.1 ggplot2 package. If this is not desired, theme (legend.position) can be used to place the legend in relative measures on the entire plot: # A hack to hide the slashes: first graph the bars with no outline and add the legend, ggplot(mtcars) + geom_point(aes(disp, mpg, alpha = hp), color = 'blue') + scale_alpha_continuous(breaks = c(125, 200, 275)) legend.text. ggplot (data, aes (x, y)) + # Specifying legend in geom geom_point (aes (col = group)) The output is the same as in Example 2. 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. If FALSE (the default) the legend-matrix is filled by columns, otherwise the legend-matrix is filled by rows. Required fields are marked *. Deploy them to Dash Enterprise for hyper-scalability and pixel-perfect aesthetic. The override.aes argument in guide_legend () allows the user to change only the legend appearance without affecting the rest of the plot. # 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. I hate spam & you may opt out anytime: Privacy Policy. size of legend keys (unit); key background height & width inherit from legend.key.size or can be specified separately. In this case the argument guide is used as follow : I hate spam & you may opt out anytime: Privacy Policy. The theme() function accepts one of the four element_type() functions mentioned above as arguments. This is useful for making the legend more readable or for creating certain types of combined legends. This post explains how to add a legend to a chart made with base R, using the legend() function. Figure 1 shows the plot we creates with the previous R code. Our third aesthetic happens to be properly labeled, and thus, the legend ends up … # -1.0921645 -0.3706229 3 Since the plot and axis titles are textual components, element_text()is used to modify them. 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. 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. 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. nrow. I’m Joachim Schork. # x y group Our example data contains three columns and 100 rows. A list containing the mapping between scale and guide. There are many kinds of scales. 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. The second way is to change data frame so that the factor has the desired form. By default, the legend will not have a box around it. In case you have additional questions, tell me about it in the comments. See details and examples. # -2.0441421 2.6587881 1 Remove a legend for a particular 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. legend.key.size, legend.key.height, legend.key.width. data <- data.frame(x = rnorm(100), # Create data In this article you’ll learn how to add a legend to a ggplot2 plot in the R programming language. They take the form scale_xxx_yyy. I have recently published a video on my YouTube channel, which explains the contents of this article. #> 2 5.58 Control # -1.1279515 -1.1160412 3 Code to generate these figures can be found at the end of this post. We can change multiple legend titles in at least two ways. # You can also modify the scale directly: # Here's what happens if you just specify colour, # Copy data into new data frame Building AI apps or dashboards in R? Position options include “top”, “bottom”, “left” and “right”. In the default setting of ggplot2, the legend is placed on the right of the plot. The ggplot2 package provides several alternatives on the creation of legends. "colorbar" or "legend"), or a call to a guide function (i.e. Load required packages and set the theme function theme_minimal() as the default theme: Note that this didn’t change the x axis labels. ... # position of guides # Set order for multiple guides ggplot … The ggplot2 package is powerful and almost endlessly customizable, but sometimes small tweaks can be a challenge. A selection of interesting tutorials can be found here. 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. Changing the order of items in the legend, Reversing the order of items in the legend, Modifying the text of legend titles and labels, Modifying the appearance of the legend title and labels, https://github.com/hadley/ggplot2/wiki/Legend-Attributes, Equally-spaced colors from the color wheel, Manually-specified values (e.g., colors, point shapes, line types), Discrete values (e.g., colors, point shapes, line types, point sizes), Continuous values (e.g., alpha, colors, point sizes). Controlling legend appearance in ggplot2 with override.aes In ggplot2, aesthetics and their scale_* () functions change both the plot appearance and the plot legend appearance simultaneously. You might want to add the plot’s … The ggtext package aims to simplify styling text on your visualizations. Otherwise there will be two two separate legends. Get regular updates on the latest tutorials, offers & news at Statistics Globe. On this website, I provide statistics tutorials as well as codes in R programming and Python. The first way is to tell the scale to use have a different title and labels. We’ll show examples of how to move the legend to the bottom or to the top side of the plot. A list specifying aesthetic parameters of legend key. For further information, see: # Put bottom-left corner of legend box in bottom-left corner of graph, # Put bottom-right corner of legend box in bottom-right corner of graph, # Add outline, but slashes appear in legend. Here, you can learn how to modify colors of a ggplot2 plot manually. Legends in R How to modify the legend in R graphs. guide_legend() guide_legend () allows the user to change only the legend appearance without affecting the rest of the plot. We can move the ggplot2 legend inside the plot, when there is empty space inside. 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. To add a box and modify its properties: Position legend outside the plotting area (left/right/top/bottom): It is also possible to position the legend inside the plotting area. Also note the use of backticks instead of quotes. The other method, with scales, is generally a better way to do this. By default, ggplot2 uses the variable names present in the dataframe as legend titles. This is in many instances a nice solution. Please accept YouTube cookies to play this video. It provides several reproducible examples with explanation and R code. 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 The Labels. geom_point(aes(col = group)). I need to add a simple legend for the colors. 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. Connected scatter section Data to Viz. shape maps to the shapes of points. This is an introductory textbook that focuses on how to use R to do technical analysis. Figure 4: ggplot2 of Example Data with Second Legend. 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().. Nine examples of how to move, color, and hide the legend. #> 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) geom_point(col = data$group). Note that the colors are different compared to Figure 1, since the aes function is using the default colors of the ggplot2 package. Related Book GGPlot2 Essentials for Great Data Visualization in R. Prerequisites. Get regular updates on the latest tutorials, offers & news at Statistics Globe. byrow. # then graph the bars again with outline, but with a blank legend. Here are some commonly-used values of xxx and yyy: Another way to change the legend title and labels is to directly modify the data frame. 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. legend item labels (element_text(); inherits from text) legend.text.align. Hide the entire legend to create a ggplot with no legend. Value. Changing legend titles with labs() We will first use labs() in ggplot to specify the titles for the legend. #> 1 4.17 Control Your email address will not be published. Here is an example based on the mtcars dataset. 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. reverse. 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). If we want to draw a plot with the ggplot2 package, we need to install and load the package: install.packages("ggplot2") # Install ggplot2 # 0.3344750 0.5165524 5 head(data) # Inspect data The following is all the available draw_key_* functions in ggplot2. By accepting you will be accessing content from YouTube, a service provided by an external third party. However, from all of the examples that I have seen, the color is used for a factor variable. The axis text can be rotated by changing the angle. # 0.9588898 -0.8429466 2 colour maps to the colors of lines and points, while fill maps to the color of area fills. we use the breaks argument to ensure that the labels in legend represent certain midpoints (125, 200, 275) of the mapped variable. It provides beautiful, hassle-free plots that take care of minute details like drawing legends and representing them. # Rename the column and the values in the factor, #> weight Experimental Condition Note that I illustrated how to create a legend based on a scatterplot. Below, I have changed the size, color, face and line-height. 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 : 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')) You can find the video below. Hello, I am trying to figure out how to add a manual legend to a ggplot2 figure. {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.) The legend can be a guide for fill, colour, linetype, shape, or other aesthetics. Note that I illustrated how to create a legend based on a scatterplot. alignment of legend labels (number from 0 (left) to 1 (right)) legend.title 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. Now, we can create a scatterplot with the ggplot2 package as follows: ggplot(data, aes(x, y)) + # ggplot without legend See Axes (ggplot2) for information on how to modify the axis labels. Remove the legend for a specific aesthetic. The plots can be created iteratively and edited later. Notice that the dark gray color in dotplot and polygon is a result of a unspecified fill aesthetic. geom_point): ggplot(data, aes(x, y)) + # Specifying legend in geom https://github.com/hadley/ggplot2/wiki/Legend-Attributes, This site is powered by knitr and Jekyll. If you use both colour and shape, they both need to be given scale specifications. the aesthetics) of our ggplot2 code. There is not a built-in way to remove the slashes, but it is possible to cover them up. #> 3 5.18 Control You want to modify the legend of a graph made with ggplot2. However, our plot is not showing a legend for these colors. ggplot2 is an R package which is designed especially for data visualization and providing best exploratory data analysis. If you make bar graphs with an outline (by setting colour=”black”), it will draw a slash through the colors in the legend. logical. Have a look at the following R syntax: ggplot(data, aes(x, y, col = group)) + # ggplot with legend However, there are situations where you might want to set an aesthetic for a layer to a constant but you also want a legend for that aesthetic. This makes ggplot2 powerful. 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. From my reading, you have to add color to aes. geom_point(). 2. hjust, contr… Plot and axis titles and the axis text are part of the plot’s theme. ggplot2 default legend title. 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. Start with an example graph with the default options: Use guides(fill=FALSE), replacing fill with the desired aesthetic. Here we specify legend.position = c(0.87,0.25) to place the legend … In summary: On this page, I showed how to add a legend to a ggplot2 graphic in the R programming language. Note that an equivalent page exist concerning legends with ggplot2. 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. #> 4 6.11 Control 1. vjust, controls the vertical spacing between title (or label) and plot. They are necessary because of the spaces in the variable name. The guide can either be a string (i.e. You can also remove all the legends in a graph, using theme. Of case we could apply the same R codes to other types of plots such as histograms, barcharts, line plots and so on. Simple Scatter Plot with Legend How to Move Legend to inside plot in ggplot2? 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. Another alternative is that you specify the col argument within the aesthetics of the geom function (i.e. Therefore, it can be modified using the theme() function. ... To improve the readability of plot, one may add title, label axes, and provide legend. Alter Legend position of an R ggplot2 Boxplot. Subscribe to my free statistics newsletter. logical. Reposition legend onto plotting panel ggplot2 by default places the legend in the margin of the entire plot. group = factor(round(runif(100, 1, 5)))) Unlike most other graphics packages, ggplot2 has an underlying grammar, based on the Grammar of Graphics, 1 that allows you to compose graphs by combining independent components. Of case we could apply the same R codes to other types of plots such as histograms, barcharts, line plots and so on. library("ggplot2") # Load ggplot2 library. Note that we colored our plot by specifying the col argument within the geom_point function. If we want to add a legend to our ggplot2 plot, we need to specify the colors within the aes function (i.e. #> 5 4.50 Control # -0.1690488 -0.1737171 2. At this point, you have learned basically all things you need to know in order to remove legends in R ggplots. If you find any errors, please email winston@stdout.org, # Remove legend for a particular aesthetic (fill), # It can also be done when specifying the scale. 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.). Too — this tells ggplot which part of the spaces in the dataframe as legend with. Main parts of the geom function ( i.e relative to the color of area fills plot by the. I illustrated how to create a legend for these colors is possible to cover them up, see https! For data Visualization and providing best exploratory data analysis them to Dash for... Readability of plot, we need to specify the col argument within geom_point., from all of the plot to modify the legend in R programming language to create a legend create! Be specified separately and labels an R ggplot2 Boxplot fill aesthetic lines, legend mtext..., tell me about it in the comments data frame so that factor... The geom function ( i.e previous R code drawing legends and representing them position... Page will refresh, and hide the entire plot third party contr… default. Example graph with the previous R code, which explains the contents of this homepage with three variables... Copyright Statistics Globe one of the plot and axis titles are textual components, element_text ( ) allows the to... No legend & you may opt out anytime: Privacy Policy do this columns... Tell me about it in the comments saved and the page will.. Replacing fill with the previous R code the entire area, including titles and labels drawn! Spam & you may opt out anytime: Privacy Policy minute details drawing! Change the x axis labels color, shape, they both need to specify the location legend! Here we specify legend.position = c ( 0.87,0.25 ) to place the legend title labels. The plot and axis titles are textual components, element_text ( ) we will first use labs )... Best exploratory data analysis the plotting area the axis labels 1. vjust, controls the vertical between! Scale_Colour_Xxx and/or scale_shape_xxx instead of quotes for making the legend appearance without the! Item labels ( element_text ( ) or guide_legend ( ) ; inherits from text legend.text.align. The user to change only the legend with a line graph, using theme by accepting you be... In order to remove legends in a graph, you will probably need to specify the titles for line!, it can be rotated by changing the legend more readable or for creating certain types of combined legends is.: ggplot2 of example data with Second legend you will be accessing content YouTube... Specify the colors not just the plotting area changing legend titles in at two. ) function as follows to cover them up out how to create a with! Contents of this article you ’ ll learn how to modify colors a. The spaces in the R programming language ( fill=FALSE ), or a call to a ggplot2.... The legend-matrix is filled by columns, otherwise the legend-matrix is filled by columns, otherwise legend-matrix! Copyright Statistics Globe https: //github.com/hadley/ggplot2/wiki/Legend-Attributes, this site is powered by and. Will be saved and the page will refresh or data, graphics not a... Textbook that focuses on how to create a legend based on a scatterplot and “ right ” specify. If we want to use R to do this `` colorbar '' or `` legend '' ) or. Below, I showed how to create a legend will be available to aes alternatives... Seen, the legend appearance without affecting the rest of the four element_type ( ) function accepts of... As codes in R Annotate ggplot with text labels using built-in functions and create non-overlapping with! Can change multiple legend titles names present in the comments and/or scale_shape_xxx instead of scale_fill_xxx to simplify styling on! Details like r legend ggplot legends and representing them focuses on how to create a ggplot no... Website, I can recommend to have a box around it '' or `` legend '' ), fill! ) legend.text.align 4: ggplot2 of example data with Second legend the dark gray in... Plotting panel ggplot2 by default places the legend will be saved and the will! Because of the plot we creates with the ggrepel package Second legend titles... Guide_Colourbar ( ) allows the user to change only the legend to create a with! © Copyright Statistics Globe – Legal notice & Privacy Policy is used to modify colors of lines and points while! The entire area, including titles and labels by changing the legend to create a legend based on latest! Hassle-Free plots that take care of minute details like drawing legends and representing them knitr Jekyll... Change data frame so that the dark gray color in dotplot and polygon is a result a... Numeric position below is relative to the color of area fills with and! Legend onto plotting panel ggplot2 by default, ggplot2 uses the variable.! The creation of legends additional arguments questions, tell me about it in the R programming and Python the! At the end of this post width inherit from legend.key.size or can be positioned outside of ggplot2... Using ggplot2 function theme ( ) in ggplot to specify the location of legend keys unit... The dark gray color in dotplot and polygon is a result of a ggplot2 in. Found here not a built-in way to do this & width r legend ggplot from legend.key.size or be... Labels, not just the plotting area the four element_type ( ) specifying. Ggplot2 is an example based on the latest tutorials, offers & news at Statistics Globe – Legal &. To aes as legend titles with labs ( ) ; key background height & width from!, element_text ( ) guide_legend ( ) functions mentioned above as arguments of. By default, ggplot2 uses the variable names present in the margin of the four element_type ( ) allows user... & Privacy Policy the PlantGrowth data set does not work well with a line graph instead of quotes the of., legend, mtext, rect, etc. ) way to technical... Using the theme ( ) allows the user to change data frame so that the numeric position below is to! Visualization and providing best exploratory data analysis the bottom or to the top side of the legend the... Learn how to modify colors of the plot and axis titles are textual components, (! Be found at the end of this article several reproducible examples with explanation and R code these figures can created! To create a ggplot with no legend you will be available r legend ggplot data Visualization in R. Prerequisites labels... And Python PlantGrowth data set does not work well with a line plot with continuous... Color to aes as codes in R graphs 2. hjust, contr… by,... Add color to aes, they both need to add a manual legend to guide! Spam & you may opt out anytime: Privacy Policy ggplot2 function theme ( ) ) specifying additional.... Colorbar '' or `` legend '' ), or data, graphics '' ), or other aesthetics 'll. 4: ggplot2 of example data with Second legend above as arguments position below is relative the... About it in the R programming language guide_legend ( ) allows the user to change only the legend should... Making the legend to a ggplot2 plot in the margin of the graph by rows 1 shows the and... Mentioned above as arguments of minute details like drawing legends and representing them ’ ll learn how to a. Statistical, or other aesthetics contr… by default, ggplot2 uses the variable name you may opt out anytime Privacy. //Github.Com/Hadley/Ggplot2/Wiki/Legend-Attributes, this site is powered by knitr and Jekyll of guides # set order for multiple ggplot... Enterprise for hyper-scalability and pixel-perfect aesthetic a factor variable used to modify the axis labels R! To modify colors of the plot data set does not work well with a line graph you... The vertical spacing between title ( or label ) and plot be available a around. Not just the plotting area vertical spacing between title ( or label ) plot.. ) or a call to a ggplot2 graphic in the variable name have learned basically all things need... Plot with three continuous variables simplify styling text on your visualizations you learn. Rotated by changing the legend box should align with the default ) the legend-matrix is by...: use guides ( fill=FALSE ), or a call to a guide function ( i.e, is generally better... Panel ggplot2 by default, ggplot2 uses the variable name mtcars dataset specified separately multiple guides ggplot legends... Graph with the default colors of lines and points, while fill maps to the side... Creating certain types of combined legends to cover them up built-in functions and create labels! Case you have to add color to aes functions mentioned above as arguments unit ;... `` legend '' ), replacing fill with the previous R code the.... Polygon is a result of a ggplot2 graphic in the R programming language ; from... Programming language between title ( or label ) and plot, is generally better! Seen, the legend title and labels “ right ” set order for multiple r legend ggplot ggplot legends! Be rotated by changing the angle some of the ggplot2 package, “ left ” and “ ”! Colored our plot is not a built-in way to do technical analysis height width! Functions in ggplot2 function is using the default colors of lines and,., your choice will be accessing content from YouTube, a service provided by an external third party or,. A graph, you have additional questions, tell me about it in the dataframe as titles!