@laupremmah The last Input part of your original attachment (which I deleted in my attachment) contained a large unterminated Image part which is where the corruption starts (many null characters). I don't see anything valid and recoverable after that, but perhaps someone else will.

Specifically, the original seems to be all null characters after the corrupted Image in Section "5)" of Section "MAT 6.1" of Section "Lektion 18 Tyngdepunkt af volumer" of Section "Matematik".

It's a shame that Maple's GUI doesn't recover even the valid portions: deleting the null characters and invalid .png Image, and also closing off the outstanding XML tags.

@laupremmah Joe's DeleteBadCharacters procedure is not going to be able to fix this (at least not by itself) since the problem is not (just) bad characters. The document also has unterminated XML tags. See my Answer below.

Do the Python examples work for you in your Maple 2018.0 without the Microsoft Visual C++ 2015 redistributable?

@mweisbr Using your second example with the P132.xlsx data file, that has purported erroneous values above 4000.

interp_ex2.mw

Are you trying to say that you want to see only the contour (level curve) at z=0.1 ?

Yes, in MapleV R5 (released in the year 1998) the command 0^0 produces "Error, 0^0 is undefined".

But in Maple 6 (released in the year 2000) and later versions, it produces 1.  And 0.0 raised to 0.0 produces Float(undefined). There is a practical balance between throwing an error and raising an exception (or setting an exception flag), and that is meant to reflect the need to allow numeric programming to be done while preventing or flagging invalid operations.

See vv's Answer for a link to more explanation.

@Adam Ledger The global name :-phi is unassigned and using it in a function call returns unevaluated. It doesn't compute anything.

It is a bug in Maple 16 that accessing an Equation Label that contains the unassigned global name :-phi will insert something with the rebound name. In your example (where you did with(numtheory) and so rebound the name), it is a bug that the global name :-phi gets inserted from the Equation Label as numtheory:-phi.

So you original only "worked" when using the Equation Label due to that bug. Maple 2018.0 doesn't have that bug, as far as I see.

Note that in your example the Math Container contained calls to just the unadorned name phi. When you extract the expression from that component the result contains just global :-phi even if you have loaded numtheory.  (It is moot whether that's the best behavior.)

Given that behavior of Math Conponents, these two workarounds are possible.
1) Substitute :-phi=numtheory:-phi into the expression extracted by GetProperty (as I showed).
2) Put numtheory:-phi explicitly into the Math Container (which you may find less visually attractive).

You may notice that there was no need for calls to simplify. Even in your original "working" instance, via the Equation Label, the simplify did nothing. Evaluate the Equation Label alone, as input, and you'll see the list of zeroes directly (because it picks up the rebound phi).

If you set up FTest to use an expression containing numtheory:-phi instead of :-phi then the calls to that will immediately resolve for posint arguments.

What platform are you using?

Is it 32-bit Maple on MS-Windows?

@abhilashun It wasn't clear (to me) that you wanted the inner portion, sorry.

It can be obtained, with the same kind of approach, using F1[3] and F1[4]. I'll try to find time for it later in the day.

The outer shell was made as an intersection. Would you want the inner shell as a union?

@JBrew13 

That's interesting because when I execute your Document (either block by block, or with the menbar's `!!!`) it works OK.

I wonder how you were attempting to execute that convert input. Was it just mouse focus, and hitting Enter? Or by selecting part or all of it? Execution from the entry in the right context-panel, or via Edit->Execute from the menubar, or keyboard acceleration like Ctl-=?

Is this Windows (32 or 64bit), OSX, or Linux?

Could you upload a worksheet/document that contains the problem? (big green up arrow in mapleprimes editor).

@Kitonum I deliberately did it the way I did, despite knowing several direct one-liners for it.

I made that choice partly because the OP on stackexchange wrote he already knew the result, but just needed to be able to enter it in Maple.

I'll note that I also wrote several sub-steps separately, deliberately repeating operations.

I was trying to illustrate the `@@` syntax (for the functional inverse), and demonstrate that Maple's `diff` command understands it, more than explain how to obtain the answer directly.

Apart from Kitonum's fine answer below, you could also see previous answers here. 

See my answer here.

@Muhammad Usman You may want to check the signs (plus, minus) in the T[w]-T[infinity] and -C[w]+C[infinity] , since your DE6 had them with both the same sign. I'm guessing that you intended a subtraction, so I changed in in DE6 below. 

Download Help_2_ac.mw