William Stein wrote: > On Wed, Jul 22, 2009 at 11:49 AM, Robert > Bradshaw<rober...@math.washington.edu> wrote: >> On Jul 22, 2009, at 11:24 AM, William Stein wrote: >> >>> On Wed, Jul 22, 2009 at 11:19 AM, Ethan Van >>> Andel<evlu...@gmail.com> wrote: >>>> In list_plot there's some confusion with the pointsize and thickness >>>> keyword arguments. >>>> >>>> These 2 commands run just fine. >>>> list_plot([(0,0),(1,1)],thickness = 20,plotjoined = true) >>>> list_plot([(0,0),(1,1)],pointsize = 20,plotjoined = false) >>>> >>>> This one runs but ignores thickness and gives you a warning saying >>>> that it is ignoring thickness. >>>> list_plot([(0,0),(1,1)],thickness = 20,plotjoined = false) >>>> >>>> This one doesn't run at all but gives you an invalid option error. >>>> >>>> This behavior is needlessly finnicky, especially when writing >>>> functions that call list_plot with user supplied parameters. For >>>> example, this method would fail half of the time. >>>> >>>> def foo(size,joined): >>>> return list_plot(mydata,pointsize = size, plotjoined = joined) >>>> >>>> My first thought for a fix was to make the arguments interchangable, >>>> ie thickness = 5 and pointsize = 5 would do the same thing in both >>>> joined and discrete plots. However, they don't actually behave the >>>> same. For example, the line drawn with thickness = 20 is much thicker >>>> than a point with pointsize = 20. Therefore, if they were to be >>>> merged >>>> in some way what would be the best way to go about it? >>> I have always found the value of pointsize to be very mysterious. I >>> wonder if we >>> could make it so pointsize=20 and thickness=20 are the same. This >>> would of course >>> break all existing use of pointsize, but at least it would make sense. >>> >>> I have heard many people chuckle when wondering what the pointsize >>> units are.
I believe it is the same as matplotlib: http://matplotlib.sourceforge.net/api/axes_api.html?highlight=scatter#matplotlib.axes.Axes.scatter "size in points^2." so pointsize=100 corresponds to 10 points, I think. I think "pointsize" refers to (a constant times) the area of the plotted point, which is not to be confused with "point", the unit of measurement (1/72 of an inch or something). At least, that's what I think after looking at the source for about 1 minute. I may be just making this all up :). I remember puzzling over this before too. Thanks, Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
