One should think so, but it doesn't.

Conventional notation would have the 2x2 matrix left, the column vector to the right, so 

print "   result: ", $matrixM x $matrixX_assigned_value;

[download]
but that complains 
PDL: Dim mismatch in matmult of [2x2] x [2x1]: 2 != 1

[download]
Swapping the factors 
print "should be: ", $matrixB_assigned_value;
print "   result: ", $matrixX_assigned_value x $matrixM;

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prints 
should be:
[
 [
  [5 8]
 ]
 [
  [10 -5]
 ]
]
   result:
[
 [
  [5 4]
 ]
 [
  [ 4 -5]
 ]
]

[download]
The result looks like a column vector, but is numerically incorrect.

BTW, it helps to cast the piddles into the PDL::Complex data type, using the cplx function. That overloads stringification so that the complex elements are printed in a x + i*y format instead of looking like pairs of reals. The numeric discrepancy remains, however.

Anno

In reply to Re^2: PDL::Complex question by Anno
in thread PDL::Complex question by gmacfadden

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