MaplePrimes - Maple 2026 Posts and Questions

pdsolve and finite difference method discrepancy

wingho — Thu, 14 May 2026 15:58:52 Z

I was using pdsolve to solve for a 1-D longitudinal wave equation. My particular problem added an external stimulus that is not mechanical in original, so the acoustic wave velocity has to be modeled as a variable c(H) and I also have to add a du/dx term in the model. You can see my question posted on April 17, 2026. I was told that pdsolve does not handle such a problem. The suggestion in the posting is to use a finite difference method.

I am verifying that approach by solving a simplier problem where c is constant but with an initial uniformly stretched material. The solution does not seem to be physical. The material should relax throughout the whole length of the material, but the solution shows relaxation at the end and stay uniformly stretched at the center. I ran the problem with pdsolve and get a different result that I think is more realistic.

Is there something I can tweak in the finite difference approach to overcome that issue?

pde_finite_difference_method_linear_ic.mw

pdsolve_exercise_damping_ini_linear_a.mw

Calling object method in debugger

nm — Wed, 13 May 2026 17:47:51 Z

Is there a workaround to being able to call object method inside the debugger? I use Objects everywhere and hard to debug things when not able to try calls inside the debugger.

Here is an example.

This worksheet below has the code to reproduce this. Ofcourse the code works when I run it in the debugger using "continue" button, or using the "next" or "step". But I need sometimes to check something before doing this.

>	interface(version);

restart;

>	kernelopts('assertlevel'=2):

>	module person_type() option object; local _name::string:=""; export ModuleCopy::static := proc( _self::person_type, proto::person_type, name::string) _name:=name; NULL; end proc; export get_name::static:=proc(_self) _self:-_name; end proc; end module;

>	foo:=proc(o::person_type)::string; local name; DEBUG(); name:=o:-get_name(); name; end proc;

>	o:=Object(person_type,"me");

>	o:-get_name();

>	#run this. Debugger will now open foo(o);

Download why_calling_object_fail_in_debugger.mw

plotting an 1-D array

wingho — Mon, 11 May 2026 20:14:59 Z

Please see the attached worksheet:

Question 1: How to plot a partial portion of an array s2 using "dataplot," say the first 50 elements.

Question 2: I have also tried to use "plot" to plot the first 50 elements s2 and keep on getting errors or strange looking plot with horizontal lines. I have tried plot(s2,1..50), plot(s2,x=1..50), plot(s2,m=1..50), plot(s2[m],m=1..50), plot(s2[1..50],1..50], plot(1..50,s2[1..50]).

plot_exercise_a.mw

Maple 2026.1 shows a wrong version

LolaMund — Wed, 06 May 2026 04:59:15 Z

> kernelopts(version);
Maple 2026.0, X86 64 LINUX, Apr 28 2026, Build ID 2011354

Deleting a column from a DataFrame?

nmacsai — Tue, 05 May 2026 15:21:10 Z

Is the implementation of DataFrames in Maple antiquated compared to PANDAS or other modern implementations of DataFrames? Even doing the most basic tasks is extremely difficult or unintuitive. I have lived in the DataFrame help pages for 5 years and I still can't delete a column from a DataFrame. Will I ever get any work done?

delete_a_dataframe_column.mw

Color option in context-panel

Geoff — Mon, 04 May 2026 04:53:53 Z

Color option in Context Panel does not work

Steps to Reproduce:
1. Create or open a histogram.
2. Try to change its color using the Color option in the Context Panel.
3. Observe that the color does not change.
4. Click outside the histogram.
5. Click back on the histogram.
6. Try the Color option again — now it works.

Expected Behavior:
The Color option should work immediately when applied to the histogram, without requiring extra clicks.

Actual Behavior:
The Color option only works after clicking outside the histogram and then reselecting it.