Hi,
I would do:
use v5.12;
use PDL;
use PDL::Constants qw(PI);
use PDL::IO::Misc;
# 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
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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