sand15

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These are replies submitted by sand15

@Carl Love 

 

By the way, thanks for making me discover the syntax op([2, 1, 1, 2], ...)
It is shorter (maybe slightly less clear) than op(2, op(1, ....) that I used to use

@Kitonum 

Than you.
It is exactly what I was expecting.

So I take it that Maple implicitely selects the first interval [-Pi/2, +Pi/2] when   solve(sin(x)=y,x)    returns   arcsin(y)

@vv

You write
 "First note that there is not such thing as "global inverse" of f, unless f (supposed to be C^1) is strictly monotonic."
Thank you vv for this quick math reminder but I know this perfectly.

Maybe I should have written
I want to construct some kind of pseudo global inverse of f over R by putting "side by side" local inverse functions
instead of
I want to construct the global inverse of f over R by putting "side by side" local inverse functions
to be clearer ?

I had thought that I was clear enough when saying
     The idea is to define the global inverse g of f over R by
     g := y ->  piecewise(y < f(a__1), g__0(y), ..., y < f(a__n), g__(n-1)(y))
    where g__p(y), is the inverse function of the restriction of f to ] a__p, a__(p+1) [

I realize it was not the case ...  or maybe you where too scandalized (with good reason) by reading the first lines (find the inverse of a non monotonic function) that you did not keep reading the rest of my question ?
I do not hold this against you: "This function is not strictly monotonic over R [and] I want to construct [its] global inverse" is really disturbing and I guess that hearing this would make me hit the roof too.

@Carl Love 

 

Thank you Carl.
My today problem concerns a polynomial function f, then your answer will be very valuable.

By the way: I have always been surprised that  solve(sin(x)=y, x)  returns arcsin(y), just as if the inverse of "sin" was defined everywhere.
If it is not too much to ask could you say a little more about this ?

Thank for all

@Kitonum 

Thank you Kitonum.

I'm often puzzled with the differences of behavior between  -> and unapply ... I guess I have to read more carefully the dedicated helps pages ...

@acer

Thanks acer
Loading 2015.2 here is not easily due to the very strict safety policy 

Nevertheless I will test this tomorrow with (some) version 2016.
Maybe I will join you later on from home, where I use 2015.2 on a imac.

Thanks again

@acer 

Here it is

Issue.mw

@Daniel Skoog 

Thanks Daniel,

I have just gave some info to acer.

About point 1 : this is a very interesting way to customize the DataSummary procedure
Concerning  your point 2 : right, a screenshot is a roundabout way to answer the question.

Thanks also for your last line, I appreciate that

@acer 

Thank you acer.

I had aleady tried the plotsetup(jpeg, ...) command but I had got an error saying the embeded summary was not of plot type (did not tried textplot : I'm going to see righr now).
What do I mean by "save this table" : you are right, this is not clear. I mean "ideally" save the appearance of the table as an image ... just like some image capture tool could do.
Of course I could use fprintf to save these informations in a text file in a "smart" form, but I found that the appearance of
DataSummarize(...summarize=embed) was realy very smart.


 

@vv 

It looks like our replies have crossed

@vv 

I found myself the solution :-)
I just  declared  use plots  within the procedure and it  works correctly now.

(I thought that loading the package plots in the worksheet itself would be sufficient)

Sorry for the inconvenience

 

@vv 

This works well but your answer made me realize that  I oversimplified my problem.
If it's not too much to ask, could you answer this one please ?


 f := proc(DrawThis)
     plotsetup(jpeg, plotoutput=SomeJpegFile);
     print(DrawThis)
     plotsetup(default);
end proc;

MyPlot := plot(x, x=0..1)
f(MyPlot);   # That's fine, thank you,

MyPlot := display(plot(x, x=0..1), plot(x^2, x=0..1))
f(MyPlot);   # No file is created

Even this simplified procedure
 f := proc(DrawThis)
     print(DrawThis)
end proc;

returns what I would have obtained by writting
MyPlot := display(plot(x, x=0..1), plot(x^2, x=0..1)) ;


Could you help me please ?

@acer 
Thanks a lot for your fruitful help.
I tested tou .mw file and it works beond my expectations.

 

@tomleslie 

I am going to implement these two solutions and look what happens on my machine.

Thanks again

@tomleslie 

 

It works perfectly well

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