I do not know if it's related to the long time elapsed from above posts, but I do not see any attachment ... attached. If some one is reading this message and has at his disposal the missing attachment(s), I'd be gratefully indebted if he can share with the community. Personally, I have the same import problem (of a Touchstone S2P file), and having at my disposal the code developed by the above fellow members would be very useful.

Hello Enrico,

I don't know how to find any of the attachments, however I found a sample S2P file here. I used the first file in their list. I attach a notebook which reads this file and extracts the s parameter data. I could not attach the file I used since both s2p and zip are not allowed as attachments.

Kind regards, David

Attachments:

Import S2P.nb

Thank you Isaac. That is quite clear with the verbose presentation. I might be able to make snippets of it available.

FWIW, the line beginning with a hash is not a comment in a Touchstone file - it must have one, and only one of those lines. I realize that point is nothing to do with the solution though.

Dave

You could select all lines which contain 3 numbers. I also copied your data as shown, with white space as word separators and newlines as record separators. The code below imports the data then selects lines which contain exactly 3 Reals.

In[16]:= SetDirectory[NotebookDirectory[]];

In[17]:= dataAll = Import["touchstone.txt", "Table"] // N;

In[18]:= dataNum = Cases[dataAll, {_Real, _Real, _Real}]

Out[18]= {{50., 0.07349, 179.648}, {62.5, -0.00239, 179.211}}

(For future reference, it would be useful to attach a sample data file to such questions.)

Kind regards,

David

Edit: The code shown assumes the data file is in the same directory as the notebook. It also assumes no pre-processing.

Attachments:

For attaching, you might try changing the file extension to ".txt" -- the specification "Table" in the Import function will interpret the file as a table no matter the extension, so code that works with the text file will also work with ".s1p". Also you might look at lower level input functions, especially ReadList with the option RecordLists->True.

--David

Edit: I've attached a short notebook. It's in version 10 -- which I highly recommend -- but I think the functionality in use was available much earlier.

Attachments:

I copied your data file into a "touchstone.txt", and the following sequence produces a usable list-of-(numeric)lists.

(*Import the data from $HomeDirectory/touchstone.txt*)
dataAll = Import["touchstone.txt", "CSV"];

(* From the simple example, we can tell by visual inspection that the \
numbers are in lines 11 and 12. Extract them. *)
dataNum = Take[dataAll, {11, 12}]

The numbers however come up with no commas in between them as follows. We need to post-process.

{{"50.00000 0.07349 179.64844"}, {"62.50000 -0.00239 179.21094"}}

(*Add commas in between the numbers to create a usable list-of-lists \
and convert the numbers back into expressions rather than the strings \
that were read-in. *)
dataList = ToExpression[Flatten[StringSplit[#, " "] & /@ dataNum, 1]]

The result is,

{{50., 0.07349, 179.648}, {62.5, -0.00239, 179.211}}

Check to see if the numbers are real numbers or still strings by taking one and multiplying it.

In[42]:= {dataList[[1, 2]], dataList[[1, 2]]*2}

Out[42]= {0.07349, 0.14698}

The output is a list-of-(numeric)lists as desired.