@mmcdara Thank you for your answer.

@acer Thank you for your answer.

@acer In the define_external line, I deleted the RETURN:: ... phrase to get a NULL return and added "c" after the fmay_mult(a,b,c,3,3).

>fmat_mult:=define_external( 'mat_mult', LIB= "C:/Users/familee/OneDrive/Documents/Maple/DLL-example/mat_mult.dll", FORTRAN, 'a'::(ARRAY(datatype=float[8])), 'b'::(ARRAY(datatype=float[8])), 'c'::(ARRAY(datatype=float[8])), 'm'::(integer[4]), 'n'::(integer[4]) ):

The results should be the Matrix c

>fmat_mult(a,b,c,3,3)
>c
                        [30.  66.  102.]
                        [36.  81.  126.]
                        [42.  96.  150.]

@sursumCorda

I ran your program and it works. I did not make any changes to the C++ compiler.

Thanks again  

@sursumCorda 

@sursumCorda 

I added the line infolevel[compiler]:=3. I got a similar response in Maple 2023 Windows 11: Compile: Compile Command: "C:\Program Files\Maple 2023\llvm\bin\x86_64-w64-mingw32-clang++.exe" -c  -DX86_64_WINDOWS=1 -I"C:\Program Files\Maple 2023\extern\include" -O2  -w  

In Maple 2022 Windows 11, the response is: Compile: Compiling generated C code with LLVM. Then everything works.

I also have Maple 2023 running on Linux, it works fine.

Thank you for your input.

@tomleslie 

@Jean-Michel 

@Jean-Michel 

Thanks for your response.

One more try at speeding it up. Write procedure and compile it to native code. The compiled procedure is faster than any of the previous attempts found in Threads_datLoop_vs_seq.mw.

Download Compiled_datLoop_vs_seq.mw

@acer

You can adjust the column widths by using weights. Or you can manually adjust the column width by hovering the mouse over a vertical border. You get a double arrow, then you drag it.
 
I have not found a way to change the font type and size in code. A work around is to select the cell or cells and click on font type and size in the menu bar. A big drawback is that everytime you execute the worksheet the contents of the table revert back to the default font and size. I am kind of happy that I can do that, because I want to export the worksheet as a pdf.
 

lens:= [13,26,52]:
Tabulate(<header, dat>, width = 7*add(lens), widthmode = pixels, weights = lens,`=`(fillcolor, (T, i, jj) -> `if`(i = 1, LightBlue, white) ) ):;

DocTabFont_test.mw

Thank you for your time in answering my question.

@Kitonum 

I realized I should have shown that zeta = xi - beta * I.

I added negative signs to the following two lines of code:

soln1:=select(s->Re(s)>0 and -Im(s)>0, soln);

  and

imaginary_part:=-Im(L[1]);

It is a nice solution.

Thank you

@Carl Love Two thumbs up.

@Carl Love Your improvements did make it run faster by 20 to 30 percent on my computer. Using the original script before it was modified for Grid Map and your M values, I calculated values for the Array A and found the results from both methods identical - element by element.  Thanks again for your great insight to this problem. 

@Carl Love The efficiency of your code is wonderful. Your lesson is greatly appreciated. I am in the process of verifying the results. Thanks again.