> Notice that William's pointA is just (1,1), whereas yours is > point((1,1)). The reason for the unusual error message is that > > sage: line?? > > shows that if we get any error from trying to make a 2D line, it > assumes you want a 3D line.
Okay it works when I define a point with just the coordinates like you said. So is the lesson that when you pass the two points to a line: ensure that they are defined by just the coordinates otherwise it will think you are trying to make a 3d line which it can't do. But suppose I want the point to be of a certain color or size, I need to use point() like: point((1,1),rgbcolor=hue(0.75),size=100) And then pass to line() which won't work. I tried calling its attributes separately like pointA = (1,1) pointA.size = 100. Didn't work either. I notice you also added point like point(pointA), I didn't realise you could do that. > though of course you are not actually using 'a' anywhere in the > interact, but I wasn't sure exactly what your intent was so I left it > alone. Good luck! Yes you can ignore the interact 'a' variable I defined in the above program, I know it doesn't do anything now. On Jun 7, 3:51 pm, kcrisman <kcris...@gmail.com> wrote: > On Jun 7, 10:26 am, dbjohn <johndbren...@gmail.com> wrote: > > > > > Yes that code works in a single cell for me. When I put it in an > > interact and plot I get an error. Below is a simplified part of the > > program I am working on. I am using the online notebook. I find when I > > comment out the lines with myTangent the plot will display correctly, > > so there is something wrong with the line I am trying to create. > > > sage: @interact > > ... def myGraph(a = slider(-5, 5,step_size=1, default=0, label='x > > value')): > > ... plotA = plot((x^2), x) > > ... pointA = point((1,1)) > > ... myB = point((3,3)) > > ... myTangent = line([pointA, myB]) > > ... plotA += pointA > > ... plotA += myB > > ... plotA += myTangent > > ... plotA.show(aspect_ratio=1,xmin=-25, xmax=25, ymin=-25, > > ymax=25,figsize=[10, 10]) > > Compare these two. > > > > sage: pointA= (1,1) > > > sage: pointB = (2,2) > > > sage: myline = line([pointA, pointB]) > > > sage: myline > > Notice that William's pointA is just (1,1), whereas yours is > point((1,1)). The reason for the unusual error message is that > > sage: line?? > > shows that if we get any error from trying to make a 2D line, it > assumes you want a 3D line. > > Try > > @interact > def myGraph(a = slider(-5, 5,step_size=1, default=0, label='x > value')): > plotA = plot((x^2), x) > pointA = (1,1) > myB = (3,3) > myTangent = line([pointA,myB]) > plotA += point(pointA) > plotA += point(myB) > plotA += myTangent > plotA.show(aspect_ratio=1,xmin=-25, xmax=25, ymin=-25, > ymax=25,figsize=[10, 10]) > > though of course you are not actually using 'a' anywhere in the > interact, but I wasn't sure exactly what your intent was so I left it > alone. Good luck! > > To sage-devel types: would it be worth throwing a check in line for a > Graphics object consisting of one element which is one point, so that > the original thing would work, or is that behavior we don't want to > encourage? > > - kcrisman -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
