C_R

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6 years, 54 days

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These are replies submitted by C_R

@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.

@acer 

I have just seen the the print extension. This is close to what I was looking for when I initially tried convert. I really think that this should be considered as a permanent extension to convert and the context panel. Really good!!!

@dharr 
Looks like. Unfortuneatly that is not what we find in text books.

And: Why a two argument function?

2*polar(1,Pi)-polar(2,Pi);
simplify(%)
                 2 polar(1, Pi) - polar(2, Pi)

                               0

Euler would turn over in his grave if he saw how wasteful we are with screen space.

But maybe an different looking inert e could be a solution.

e^(Pi*I)
                             Pi I
                            e      

alias(e=%exp): #that is not working
e(I*Pi);       # but should describe the idea I have in mind
simplify(%)

                            e(Pi I)
                            -1

@acer
I see. Automatic simplification...

I am surprised that there is nothing provided for students.
The exponential form is so important when it comes to multiplication and division of complex numbers by hand.

It would be nice to demonstrate stepwise calcualtions/simplifications with Maple.

Brilliant ideas are needed.

Thanks

@vv 

IMO it should because it converts without ICs to the expected from.

odetest((lhs-rhs)(mysol),ode);

If this was intentionally implemented it should also work with ICs.

I would report it as a product improvement.

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