C_R

3412 Reputation

21 Badges

5 years, 316 days

MaplePrimes Activity


These are replies submitted by C_R

 

                                    

                                      

@nm 

With this one I get sdmp:-mull error

hangs_int_V3_june_16_2024_rply.mw

@nm 
Attached is the second run. The first run was aborded during trial 3 after a good hour with the interput button.
Time at the status bar was only upated after the interupt completed. (allocated pricate memory was 64 Gb at interput)

hangs_int_V2_june_16_2024_after_abort_and_rerun.mw

The new worksheet times out a factor of 3 faster.

Currently the thrid run (by !!!, without reload of the worksheet) hangs at trial 6. I saw again the memory jump to 64 Gb and the GUI time is frozen . Looks like a pattern. No sdmp:-mull error yet with the new worksheet.

On my machine the behaviour is deterministic (so far). These are the timestamps after the error message

Error, (in PDEtools/NumerDenom) time expired

243.078,481.625,683.578,923.734,1154.515,1380.953

So far, I never got another error message. The private bytes the system allocated for the mserver.exe task at termination were always around 3 Gb.

The second screen you show is unexpected.
What I have seen, when increasing the timelimit to 500, is that the private bytes jump from 3 Gb instatly to 64 Gb. Interputing at that stage takes "ages" to clear the memory.

This allocation jump also happens without timelimit. There is something strange with the integral that needs to be investigated. Did you ever get a result from int?
(This reply was on the original post. I have seen that you have send an update)

@Carl Love 

One reason more to have a dedicated (self explaining) identity function as other languages have.

@nm 

Yes, it will. I wrongly, interpreted the output combine[trig] as "can't perform". Thanks for the answer.

@Carl Love 

I only wanted to clarify pros and cons of the proposed solutions (and if there is still some room for improvement).  

I would have overlooked the Hold statement, if you had not mentionned it.
Thank you!

@nm 

My understanding of ()() is the following: The first pair of parenthesis groups functions and the second groups arguments. All functions are applied to the same group of arguments. 
Take for example

(y=sin)(x)
                         y(x) = sin(x)

In my interpretation it is somehow the opposite to the map command and the elementwise command where one function is mapped to many arguments (contained in a data structure, which type highly influences the mapping result).

The combine[trig] as well `combine/trig` call a special combine function (or better procedure, since all functions are implemented in Maple as a procedure). This is somehow not working with combine, but it worked here for a selfmade procedure. Hence the question.

@Carl Love 

Is your way an endpoint? No further mathematical manipulations seem possible.

value(make_nice(k)*8)

 

@nm 

I suspect that the multiplication symbol probably cannot be suppressed. Thanks anyway

@nm 
That's not quite what I am interested in.

I used extended typesetting by default and got used to the output. Now, that I realise that Maple is capable to produce this type output I  would like to have it everywhere. The improved readability speaks for itself. For code protability reasons I prefer as little custom procs for typesetting as possible.

I wonder why extended typesetting comes with extended fraction bars.

 

@Thomas Richard 

For the past years, I used extended and I am reluctant to change.
Is there a typesetting rule (or soemthing else) that could be set to have the same output in extended?

I agree. Question should be converted to a post

@acer 

Yes, but graphically.

For (a^3)^(1/3)

we imagine a pointer pointing at -1. Multiplication by -1 (i.e. adding pi) lets the pointer rotate counter clockwise to 1. Multiplying again by -1 rotates the pointer again counter clockwise to -1 where we startet.
Raising this result to the power of 1/3 rotates the pointer back to pi/3, which points now to a complex number.

For (a^1/3)^3

the pointer rotates first back to pi/3. Rasing this to the power of 3 rotates the pointer forward to -1 where we started.

For a=1 nothing moves in both cases.

 

@acer 

The context panel addition is interesting, but I will probably not need it very often and it risks to get lost at the next Maple update.

How did this question come up? I wanted to demonstrate why Maple does not simplify (a^3)^(1/3) without assuming positive but it does simplify, or better evaluate, (a^1/3)^3. For this I wanted to use a numeric value on the unit circle and took -1 to quickly convert and manipulate it with Maple. This did not go as swift as I though. All that originated from an ode that was not in standard form. Raising this ode to the power of 1/3 leads to complex derivatives if dy/dx is negative. To bring the ode to the standard form with Maple, simplify/symbolic must be used (vv did it by hand). I am still musing about the mathematical interpretation of this operation (and where such odes in nonstandard form come from).

Anyway, even though I am not in desperate need, the use, look and feel of a context panel entry to complete the set of manipulations (besides magnitude, argument, Re, Im and conjugate) on a complex number would be interesting. How should it be labeled to be consistent with other entries? Polar form, Exponential form or Inert exponential form?

Maybe "convert -> Polar" with two sub menus is sufficient: one producing Maple polar output and another producing inert e output. This could have an educational aspect too. Users would be informed that there is a polar way to do arithmetics and a “PolarForm” output (or the like) for a textbook style output using a new convert extension to be implemented. Users could learn without consulting the help system in the first place and easier understand why Maple is implemented the way it is.

I am not sure how to deal best with complex numbers on the real axis without prior knowledge of this

-1. + 0.*I

The context panel is the best quick reference for manipulation options I can think of. An easy way to learn Maple and math too. Why not adding conversion to a text book style output when Maples defaults do not provide this type of output?

Thank you all for this interesting exchange.

First 24 25 26 27 28 29 30 Last Page 26 of 67