On Fri, 1 Jul 2022, Luis Mochan wrote:
> # read all data, skip first row
> my ($f, $M11, $A11, $M21, $A21, $M12, $A12, $M22, $A22)=rcols "rem.s2p",
> {LINES=>"1:-1:1"};
> my $rows=$f->nelem;
> my $M=pdl($M11, $M12, $M21, $M22); # Indices: filerow, position
> my $R=pdl($A11, $A12, $A21, $A22)*PI/180; # filerow, position
> my $S=$M*exp(i()*$R); # filerow, position
> my $Sm=$S->mv(0,-1) # position, filerow
> ->reshape(2,2, $rows); # column, row, filerow
Can you explain what $S->mv(0,-1) does with respect to the -1 value? The
pdl docs don't cover what -1 means (or at least its not covered near the
`mv` function). Maybe -1 is has a standard meaning in PDL terminology?
I think I have it working for our dataset. The resulting code is more
complicated than your beautiful example because I had to handle touchstone
edge cases (like 2-port is col-major and all others are row-major) as well
as arbitrary matrix sizes (2x2, 4x4, etc)---but it works!
Questions:
Does PDL parallelize vector arithmetic somehow or do I need to do
something further to enable threading?
If so, how does it parallelize the work?
Is there anything to consider when building PDL code so it scales for
parallelization?
-Eric
> say $f, $Sm, $Sm->info;
>
> rcols would read all the data into columns. For each row $M and $R would
> have the magnitudes and the angles in radians, and $S would have the
> corresponding complex numbers. Then, for each row I rearrange the four
> corresponding $S's into a 2x2 matrix by first getting the row index
> out of the way and then doing a reshape. I ran it with a file
>
> rem2.s2p:
> Freq(MHz) MagS11 AngS11 MagS21 AngS21 MagS12 AngS12 MagS22 AngS22
> 100 0.588 50.208 0.770 -35.964 0.770 -35.964 0.588 50.208
> 200 0.589 51.209 1.771 -34.965 1.771 -34.965 1.589 51.209
> 300 1 0 1 45 1 90 1 135
>
> and obtained
>
> [100 200 300]
> [
> [
> [0.376321423329891+0.451803260659953i 0.623227336287862-0.452203148268051i]
> [0.623227336287862-0.452203148268051i 0.376321423329891+0.451803260659953i]
> ]
> [
> [0.368997536067325+0.459088029005597i 1.45133851899712-1.01491748594417i]
> [ 1.45133851899712-1.01491748594417i 0.995478921580609+1.23852441101849i]
> ]
> [
> [ 1
> 6.12323399573677e-17+i]
> [ 0.707106781186548+0.707106781186547i
> -0.707106781186547+0.707106781186548i]
> ]
> ]
> PDL: CDouble D [2,2,3]
>
> In this case, the filerow index is the last one and I assume that the
> indices in the filecolumn labels are in the usual row-column order, so
> that, for example, the S12 element corresponding to frequency 300MHz
> would be $S->at(1,0,2) (permute the 12 to 21, as pdl uses column index
> first, and substract 1 to make the indices zero-based).
>
> Hope it helps.
>
> Regards,
> Luis
>
>
> On Thu, Jun 30, 2022 at 11:59:39PM -0700, Eric Wheeler wrote:
> > Hello all,
> >
> > I'm trying to read RF touchstone (.s2p) files that are in a format like so:
> >
> > Freq(MHz) MagS11 AngS11 MagS21 AngS21 MagS12 AngS12 MagS22 AngS22
> > 100 0.588 50.208 0.770 -35.964 0.770 -35.964 0.588 50.208
> > ...
> > 200 0.589 51.209 1.771 -34.965 1.771 -34.965 1.589 51.209
> >
> > There are thousands of these lines in a file, one line for each measured
> > frequency. Each line represents a complex scattering (S-parameter) matrix
> > and the mag/angle format needs to be converted to a `cdouble` to work on
> > the matrix mathematically.
> >
> > A single-line 2x2 complex matrix might look as follows, where S_ji is a
> > complex value:
> >
> > [ S11 S12 ]
> > [ S21 S22 ]
> >
> > Since we are provided values in magnitude-angle format (in this example)
> > they must be converted to cdoubles so we can work on them. There are
> > several formats: RI, DB, and MA. For the MA (mag-angle) format this is
> > the transform where $a is mag and $b is angle:
> >
> > $complex = cos($b*pi()/180) + $a*sin($b*pi()/180) * i
> >
> > I can generate a vector of 2x4 matrices holding mag-angle pairs by reading
> > the file line by line like this:
> >
> > [
> > [
> > [ S11mag S11ang S12mag S12ang ]
> > [ S21mag S21ang S22mag S22ang ]
> > ]
> > ... for each line
> > ]
> >
> > I'm new to using PDL and at this point I'm not sure how to convert them to
> > a computable form. Since the mag/angle values need to be manipulated in
> > parallel before creating a cdouble out of them I'm not sure how to go
> > about this.
> >
> > Here are my questions:
> >
> > 1. How can I efficiently apply the
> > real = cos($b*pi()/180)
> > imag = $a*sin($b*pi()/180)
> > transform to each mag/angle pair where $a is mag and $b is angle?
> >
> > 2. How can I then (or simultaneously) convert the 2x4 real-imag matrix
> > from #1 into a 2x2 cdouble matrix to look something like this?
> >
> > [
> > [
> > [ S11 S12 ]
> > [ S21 S22 ]
> > ]
> > ... for each line where Sji are cdoubles
> > ]
> >
> > 3. Now that I've described the issue, is there a better way to do this?
> >
> >
> > Once they are in a matrix format then PDL can convert them efficiently to
> > other matrix types (T, A, Z, Y) to create parallel or series circuits with
> > matrix arithmetic at each frequency. We can then optimize the RF filter
> > circuits using component models published by manufacturers from actual
> > measurements.
> >
> > The resulting open-source tool will be comprised of Perl modules from this
> > work and published on CPAN.
> >
> > Thanks for your help!
> >
> > --
> > Eric Wheeler
> > KJ7LNW
> >
> >
> > _______________________________________________
> > pdl-general mailing list
> > pdl-general@lists.sourceforge.net
> > 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 `>/ /\
> Av. Universidad s/n CP 62210 | (*)/\/ \
> Cuernavaca, Morelos, México | moc...@fis.unam.mx /\_/\__/
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>
>
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