[PyX-user] Fonts: how to use Helvetica from the default PDF library?

[Maarten v. d. V. <m.h...@gm...>]

Dear people,

I would like to ask your help again for another issue I can’t seem to solve using the documentation and the newsletter archives. I must admit that I have practically no experience with LaTex.

Use case:
I intend to use PyX as a replacement for pyFPD, handcrafted SVG and the PIL(LOW) library. My goal is to serve custom made, free, on demand graphics.

Because of that, the font in the document should be one of the 14 Adobe standard postscript fonts, so the downloaded document can be edited in, say, Illustrator. 

Problem:
I can find out how I should do this. How can use Helvetica as the standard font for my documents?

What I tried:

        Pyx.text.set(Pyx.text.LatexEngine, texenc='utf-8')
        Pyx.text.preamble(r"\usepackage{helvetica}”)

This makes, seemingly, crash LaTex. Flask says: "Still waiting for LaTeX after 5 (of 60) seconds…”.

And another question,… how can I use the diameter symbol from LaTex? \times and \cdot work, føreing chåracters too, but the \diameter symbol yields:

  *! Undefined control sequence.

Thanks again in advance,

Maarten