C_R

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4 years, 247 days

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These are questions asked by C_R

I have tried to understand why ODESteps cannot find a solution for cases where an ODE can separated into a polynomial expression and an ODE.

or example, when I trace like this

restart;
trace(Student:-ODEs:-ODESteps:-ModuleApply);
printlevel:=10;
Student:-ODEs:-ODESteps:-ModuleApply(x*(diff(y(x), x)) = 0);
printlevel:=1

trace is tracing an unknown procedure

and not showing any further details of this procedure.
What unknow function/procedure is traced?

Can, in this particular case, the message "Cannot compute integral"   be traced (it’s not an error message, which are traceable).

I have tried to increase printlevel which reveals some unkown procedures but did not get down to this one. Hence my questions.

In the example below, the second call to simplify is ineffective

eq := (a*x + b)/(c*x + d) = 1;

`simplify/nodenom`:= x -> (numer@(lhs - rhs) = 0)(x);                       
                      
`simplify/nodenom`(eq);
simplify(eq, nodenom);

Why is that?
Convert, for example, works

`convert/nodenom`:= x -> (numer@(lhs - rhs) = 0)(x);

`convert/nodenom`(eq);
               
convert(eq, nodenom);

 

This is new:

Maple 2024 frozen on opening recent files

Maple 2023 frozen on opening

Maple 2022 frozen on opening start page

Maple 2021 blinking

Maple 2020 opening start page

The above system state is constant for about 30 min. Maple sessions without start page are working. I can enter code but file opeing and saving does not work. The fact that Maple 2020 is also not working makes it unlikely that the Java environement is part of the problem.

I have several times restarted the system. The rest of the system is working.

Something happened to the system and I have no clue what is was and what I can do about it.

Any ideas or suggestions what I could try? Windows 10.

Under piecewise in ?updates,Maple2024,AdvancedMath I find

{simplify,combine}(piecewise(x <= 0, 2*ln(1 - x), 0 < x, ln((x - 1)^2))) assuming (x, real);
                         /  /       2\\ 
                        { ln\(x - 1) / }
                         \            / 

Same result without simplify

{combine}(piecewise(x <= 0, 2*ln(1 - x), 0 < x, ln((x - 1)^2))) assuming (x, real);
                         /  /       2\\ 
                        { ln\(x - 1) / }
                         \            / 

What I do not understand is the grouping of simplify and combine in a set. This looks like a function composition which is normally done with the composition operator

(simplify@combine)(expr)

Asking differently: What is

{simplify,combine}(expr)

supposed to do in the examples?

Printlevel can be used to understand how Maple processes input. In some cases printlevel has to be increased to high values which produces an ennormeous amount of output.

In case a particular procedure has been identified for detailed analysis it would be desirable only for this procedure to set a printlevel. Kind of a local printlevel.

Does something like this or other ways exist?

trace as I understand it only traces the procedure given as argument but not levels "below".

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