Alex Smith

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16 years, 351 days

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Yesterday  the Maple 12.01 update installed on my computer.

Today, Maple 12.01 Standard does not start. Nothing happens, And after many minutes, nothing continues to happen (Douglas Hofstadter).

Maple 12.01 Classic starts--really fast.

Maybe it's the update. The other intervening factor was the very recent critical Windows secruity update.

Does anybody have a similar experience?

 

 

Maple 11 generously introduced the option smooth=true to listdensityplot. But I am finding unexpected behavior with the option. In the code below, notice how the option smooth=true ends up triggering the transform "Scale" to produce a three-dimensional plot structure, but the option smooth=false, in conjunction with "Scale", produces (as expected) a two-dimensional plot structure. Code follows: with(plottools):with(plots): sample:=[seq([seq(i*j,i=1..40)],j=1..40)]: Grid:=listdensityplot(sample,smooth=true,colorstyle=HUE,style=patchnogrid); display(Grid); Scale:=transform((x,y)->[x*2*Pi/40,y*Pi/40]):
My Calculus III students stumbled on this buggy thing while evaluating a line integral to calculate the flux The curve [X(t),Y(t)] is the right-half of a Lemniscate with polar equation R^2=cos(2*theta). The vector field is F(x,y)=M(x,y)i+N(x,y)j. They were integrating M*dy-N*dx around the curve. If we let a=M*dy and aa=expand(M*dy), then they find that Maple's int gives inconsistent results. As far as I can tell, a and its twin aa are well-behaved over -Pi/4..Pi/4 and equal. Maybe it is a bug in how Maple handles elliptic integrals? Or maybe it is some issue with removable discontinuities?
In Maple 10 today I exported a graph to eps, with the intention of using the LaTeX package psfrag to jazz up the text. I used textplot to place the tags into the eps file as I have done many times in the past--using Maple 9.5, 8, etc. To my horror, in Maple10, the textplot gets placed into the eps file in some hopelessly cryptic way, and psfrag fails to find the tags, and LaTeX replacement of the tags fails. I generated the eps file by right-clicking on the graph, and so I decided to see what happens the other way...click on the graph, select "plot" on the menu, then "export" etc. This worked, almost. I got a simpler type of an eps file, and with this file, LaTeX was able to replace the tags I put in the eps file using textplot. Almost: when I applied the functor dvi2ps, color was lost!
I find that if I start Maple10 and execute the following code, I typically end up with the warning. But if I re-execute the code once or twice again, the warning goes away and Maple evaluates the integral in terms of Elliptic functions. Great...but why should I have to re-execute the code a few times before getting a result?


> restart;
> assume(u1<0);assume(u2>0);assume(U>0);additionally(U<u2);
> assume(u0>0);additionally(u0<u2);
> u3:=1-u1-u2:
> int(1/(u^2*(1-u)*sqrt((u-u1)*(u-u2)*(u-u3))),u=u0..U):

Warning, unable to determine if 1-u1-u2~ is between u0~ and U~; try to use assump
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