Mark, I recall that some pdl functions are 'complex' aware and some are not. In particular, I believe that the 'x' matrix multiplication doesn't handle complex matrices. For example, consider the following examples
$ perl -MPDL -E '$a=pdl(1); say $a x $a;' [ [1] ] $ perl -MPDL -MPDL::Complex -E '$a=pdl(i); say $a x $a;' Dim mismatch in matmult of [2x1] x [2x1]: 2 != 1 at ... So I guess you have to do your own complex matrix multiplication, or separate real and imaginary parts and replace ($R1+i*$I1) x ($R2+i*$I2) by ($R1 x $R2 - $I1 x $I2) +i*($R1 x $I2 + $I1 x $R2 ) About the -i, perl might consider it as the string "-i" since it starts with a '-' (thus, you save on quotation marks when you use a '-' to denote parameters), but in your case it means minus the imaginary unit -&i, so perl guessed correctly but it warns you that it was an educated guess. Regards, Luis On Mon, Feb 01, 2016 at 11:21:12PM +0000, Mark Baker wrote: > > Hello All > > I have been working on some Quantum Problems and have not been able to > get PDL to produce the right results > for the Pauli matrices ... > (($x x $y) - ($y x $x)) = $z ; (($y x $z) - ($z x $y)) = $x; > (($z x $x) - ($x x $z)) = $y; > where $x = [ 0 1 ] $y = [ 0 -i ] $z = [ 1 0 ] > [ 1 0 ] [ i 0 ] [ > 0 1 ] > > yet when I try to enter -i I get this use PDL::Complex; > pdl> p $y = pdl( [ 0, -i ] , [ i, 0 ] ); > Ambiguous use of -i resolved as -&i() at (eval 91) line 4. > > [ > [ > [ 0 0] > [ 0 -1] > ] > [ > [0 1] > [0 0] > ] > ] > > and here is the answer i get when trying to use it ... > pdl> p (($z x $x) - ($x x $z)) > > [ > [ 0 2] > [-2 0] > ] > > this should be ... > > [ 0 -i ] > [ i 0 ] > and .... > pdl> p (($x x $y) - ($y x $x)); > > [ > [ > [ 0 -1] > [ 1 0] > ] > [ > [-1 0] > [ 0 1] > ] > ] > > I have two answers for this yet the one answer should be ... > > [ 1 0 ][ 0 -1 ] > Can any one help explain why (($x x $y) - ($y x $x)) = $z ; (($y x $z) - > ($z x $y)) = $x; (($z x $x) - ($x x $z)) = $y;is not working right here > ??? > Warm Regards, > -Mark > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > pdl-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/pdl-general -- o W. Luis Mochán, | tel:(52)(777)329-1734 /<(*) Instituto de Ciencias Físicas, UNAM | fax:(52)(777)317-5388 `>/ /\ Apdo. Postal 48-3, 62251 | (*)/\/ \ Cuernavaca, Morelos, México | [email protected] /\_/\__/ GPG: 791EB9EB, C949 3F81 6D9B 1191 9A16 C2DF 5F0A C52B 791E B9EB ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ pdl-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/pdl-general
