Re^3: PDL works for real number matrix operations, but not working for complex number matrix operations.

You wrote:

Equation 1: (1+i)*Xsub1 + (2+i)*Xsub2 = 5+10i

Equation 2: (1-2i)*Xsub1 + (2-i)*Xsub2 = 8 -5i
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[...]

This says that Xsub1 = 3+i, and Xsub2 = 2+i .....which is the correct result!

No, it isn't! I checked your result manually and couldn't believe what I found. So I took out PDL (which I'm not particularly familiar with) and used Math::Complex to run the following:

use Math::Complex;

my ( $m11, $m12) = ( 1 +   i, 2 + i);
my ( $m21, $m22) = ( 1 - 2*i, 2 - i);
my $b1 = 5 + 10*i;
my $b2 = 8 - 5*i;

my $xsub1 = 3 + i;
my $xsub2 = 2 + i;

my $r1 = $m11*$xsub1 + $m12*$xsub2;
my $r2 = $m21*$xsub1 + $m22*$xsub2;

print "$r1 (should be $b1)\n";
print "$r2 (should be $b2)\n";
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which prints

5+8i (should be 5+10i)
10-5i (should be 8-5i)
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Pardon me for being blunt, but you should have checked your result yourself instead of sending me (and who knows how many venerable monks more) on a wild-goose chase.

Apart from that, I don't see how you arrive at the real 4x4 matrix that you use to represent a complex 2x2 matrix. I think there is such a representation, but the one you're using is obviously wrong.

I have not followed your calculations any further. Very probably the result Math::Pari gave you is the correct one.

Anno

Update: Corrected mistaken reference to Math::Pari

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Re^4: PDL works for real number matrix operations, but not working for complex number matrix operations. by gmacfadden (Sexton) on Mar 21, 2007 at 17:00 UTC
Anno, please accept my sincere apology. I'm grateful for your's and all the monks' altruism in helping those of us trying to come up on the learning curve. I feel badly about whatever time the bespoke error caused you to waste. I will re-create a correct problem statement for my PDL question. If you can forgive this mistake, I would again value and invite your and the monk community's help.	[reply]
Re^5: PDL works for real number matrix operations, but not working for complex number matrix operations. by etj (Priest) on Jun 21, 2022 at 17:44 UTC
The differently-asked question was at PDL::Complex question. The answer was that PDL::Complex has severe limitations which can be partly mitigated by using PDL::LinearAlgebra; a more complete solution was part of PDL 2.040 with "native complex" number support.	[reply]