On Sat, Mar 14, 2009 at 11:37 AM, Burcin Erocal <bur...@erocal.org> wrote: > > On Sat, 14 Mar 2009 13:18:40 -0500 > Jason Grout <jason-s...@creativetrax.com> wrote: > >> >> William Stein wrote: >> > On Sat, Mar 14, 2009 at 11:09 AM, Jason Grout >> > <jason-s...@creativetrax.com> wrote: >> >> William Stein wrote: >> >>> On Sat, Mar 14, 2009 at 10:29 AM, Carl Witty >> >>> <carl.wi...@gmail.com> wrote: >> >>>> 2) plotting >> >>>> A lot of the plotting code is willing to pick variable names (in >> >>>> alphabetical order) if names aren't given in the plot ranges. >> >>>> For instance, this is a doctest in plot.py: >> >>>> sage: f = sin(x^2 + y^2)*cos(x)*sin(y) >> >>>> sage: c = contour_plot(f, (-4, 4), (-4, 4), plot_points=100) >> >>>> This will be deprecated, but any of the following will work: >> >>> -1 >> >>> >> >>> I'm strongly against deprecating anything like this for plotting, >> >>> since there are clear labeled axes in the plot. >> >>> >> >>>> sage: c = contour_plot(f, (x, -4, 4), (y, -4, 4), >> >>>> plot_points=100) sage: c = contour_plot(f.function(x, y), (-4, >> >>>> 4), (-4, 4), plot_points=100) sage: c = contour_plot(lambda x,y: >> >>>> f(x=x,y=y), (-4, 4), (-4, 4), plot_points=100) >> >>>> >> >> >> >> I'm just as strongly for the deprecation. The axes are *not* >> >> clearly labeled: it's not clear which axis is which because there >> >> are no variable names next to the axes. Even if we fixed that >> >> issue, though, it is not clear to the user how to switch the axes >> >> if they are opposite from what they want. contour_plot(f, >> >> (x,-4,4), (y,-4,4)) makes it intuitive that if you want to swap >> >> roles of the axes, you swap the ranges. Explicit is better than >> >> implicit, I feel, in this case. >> >> >> > >> > Well then we disagree. There is a very standard convention in math >> > to have the x axis in one spot, then the y-axis. >> >> What happens when you have variables u and v? Or a and b? Or t and >> s (oops, I mean s and t; I forgot the alphabetical order; see? it's >> easy to mess up; but t is often the x-axis, regardless of what the >> other variable is called, even if it is alphabetically >> smaller... :). What about variables some_long_name and >> some_long_mame? It's much harder then to figure out which gets >> magically picked as the x-axis. > > I agree with Jason here. I think the variables should be specified > explicitly. > > William, shall we treat the case where the only variables in the > expression is x and y specially, and allow not specifying the variables > for the axis then? I think this makes the notation confusing and > inconsistent. >
I have never ever even once heard of somebody complaining or being serious confused because these pop up a plot: sage: sage: plot(sin(u), (-3,3)) sage: plot3d(x^2 + y^2, (0,3), (-2,3)) I have frequently seen and heard of people being confused by sage: x(5) 5 Just for historical perspective, when plot was written there was no symbolic ring in sage and no symbolic variables, so putting (x,0,3) made no sense... -- William --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
