Minimal pair:

perl -MPDL -MPDL::Matrix -e '$m = mpdl [[2,0],[0,2]]; $v = vpdl [1,2];
+ print $m x $v'

[
 [2]
 [4]
]

[download]

vs.

perl -MPDL -MPDL::Matrix -e '$m = mpdl [[2,0],[0,2]]; $v = vpdl [1,2];
+ print inv($m) x $v'
Dim mismatch in matmult of [2x2] x [2x1]: 2 != 1 at /usr/lib64/perl5/v
+endor_perl/PDL/Primitive.pm line 274.
    PDL::matmult(PDL=SCALAR(0x5600a82130e0), PDL::Matrix=SCALAR(0x5600
+a8202ba0), PDL=SCALAR(0x5600a8d718c8)) called at /usr/lib64/perl5/ven
+dor_perl/PDL/Primitive.pm line 31
    PDL::__ANON__(PDL=SCALAR(0x5600a82130e0), PDL::Matrix=SCALAR(0x560
+0a8202ba0), "") called at -e line 1

[download]

This looks like a bug in PDL::Matrix, specifically with inv.

In reply to Re^4: Abstract image registration or feature detection by kikuchiyo
in thread Abstract image registration or feature detection [UPDATED w examples] by kikuchiyo

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