On 28/07/18 17:03, Jeff Newmiller wrote:
When you understand the strong dependence on how the data controls ggplot, using it gets much easier. I still have to google details sometimes though. Note that it can be very difficult to make a weird plot (e.g. multiple parallel axes) in ggplot because it is very internally consistent... a blessing and a curse.1) Colour is assigned in the scale according to order of levels of the factor. Note that while they are both discrete, the so-called "discrete" scales auto-colour, but "manual" scales require you to specify the exact colour sequence.2) Assigning constants to properties is done outside the mapping (aes). Note that "colour" is for lines and shapes outlines, while "fill" is colour meant to fill in shapes. When the names of these two scales are the same and the values are the same, the legends will merge. If not, they will be shown separately.3) Discrete scales are controlled by the levels in the data. To prevent ggplot from removing missing levels, use the drop=FALSE argument.4) Breaks are a property of the scale. My changes were: Year <- factor( rep( 4:8, each = 50, times = 2 ), levels = 0:8 ) DemoDat <- data.frame(Year = Year, Score = c( X0 , X1 ), Type = Type ) ggplot( data = DemoDat , aes( x = Year, y = Score, color = Type ) , fill = NULL ) + geom_boxplot( position = position_dodge(1) ) + theme_minimal() + scale_colour_manual( name = "National v. Local" , values = c( "red", "black" ) ) + scale_x_discrete( drop = FALSE ) + scale_y_continuous( breaks = seq( 700, 2100, 100 ) ) Good luck with your graphics grammar!
Dear Jeff,Thanks very much for this cogent advice and for taking the trouble to steer me in the right direction. However I am not quite out of the woods yet.
(1) I'm still getting two legends. How do I stop this from happening?(2) The boxes are "filled" (with pinkish and blueish colours --- which are referenced in the second of the two legends that I get). How can I get "unfilled" boxes?
(3) The y-axis scale runs only from 800 to 1800, rather than from 700 to 2100. How can I force it to run from 700 to 2100?
(4) With the modified code we now get some "outliers" (points beyond the whisker tips) plotted --- which I didn't get before (and don't want, because "last year's" graphics did not include outliers). How can I suppress the plotting of outliers?
I have attached a pdf containing the results of running the code that you provided, so that you can readily see what is happening. May I prevail upon your good graces to enlighten me about questions (1) --- (4) above? Ever so humbly grateful. cheers, Rolf -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
demoPlot.pdf
Description: Adobe PDF document
______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
