# tex problem

Hi,

I have different questions to use tex with matplotlib.

The first one:

If I'm doing:

rc('text', usetex=True)
xlabel('$\textrm{toto}$') # bad
xlabel(r'$\textrm{toto}$') # ok

The results are not the same and I don't understand why.

and for:

xlabel('$\textit{toto}$') #bad
xlabel(r'$\textit{toto}$') #ok

same things, but it's working fine for:

xlabel('$\it{toto}$') #ok
xlabel(r'$\it{toto}$') #ok

but it's not working for \bf:

xlabel('$\textbf{toto}$') # bad
xlabel(r'$\textbf{toto}$') # ok
xlabel('$\bf{toto}$') # bad
xlabel(r'$\bf{toto}$') # ok

And this bring to the second question, I would like to create the xlabel with
latex stuf inside somewhere in my script:

label='$\textrm{test}_2$'

but that can't work:

How to tell that I want the "r" before the chains to have TeX working like
expected?

Thanks,

N.

humufr@...136... wrote:

Hi,

I have different questions to use tex with matplotlib.

The first one:

If I'm doing:

rc('text', usetex=True)
xlabel('$\textrm{toto}$') # bad
xlabel(r'$\textrm{toto}$') # ok

The results are not the same and I don't understand why.

and for:

xlabel('$\textit{toto}$') #bad
xlabel(r'$\textit{toto}$') #ok

same things, but it's working fine for:

xlabel('$\it{toto}$') #ok
xlabel(r'$\it{toto}$') #ok

but it's not working for \bf:

xlabel('$\textbf{toto}$') # bad
xlabel(r'$\textbf{toto}$') # ok
xlabel('$\bf{toto}$') # bad
xlabel(r'$\bf{toto}$') # ok

And this bring to the second question, I would like to create the xlabel with latex stuf inside somewhere in my script:

label='$\textrm{test}_2$'

but that can't work:

How to tell that I want the "r" before the chains to have TeX working like expected?

I think you have much to gain and nothing to lose by *always* using raw strings for TeX. The reason your "bad" cases are bad is that \b and \t are escape sequences; in an ordinary string, without the leading r, the two-character sequences are translated into control characters (bell and tab, respectively). \i is not an escape sequence, so it gets left alone.

Eric

I agree with you but how can I use the raw strings when I want to compose a
text (2nd question)

I tried:

label='$\textrm{test}_2$
xlabel(r label)
xlabel(r+label)

etc but it not working (like I expected). So I would like to know if there are
a way to precise that the text is a raw string by another thing that the r
character just before the string. Perhaps that will be good to have an option
like raw=true or something similar?

Thanks,

N.

···

Le Mardi 31 Octobre 2006 23:14, Eric Firing a écrit :

humufr@...136... wrote:
> Hi,
>
> I have different questions to use tex with matplotlib.
>
> The first one:
>
> If I'm doing:
>
> rc('text', usetex=True)
> xlabel('$\textrm{toto}$') # bad
> xlabel(r'$\textrm{toto}$') # ok
>
> The results are not the same and I don't understand why.
>
> and for:
>
> xlabel('$\textit{toto}$') #bad
> xlabel(r'$\textit{toto}$') #ok
>
> same things, but it's working fine for:
>
> xlabel('$\it{toto}$') #ok
> xlabel(r'$\it{toto}$') #ok
>
> but it's not working for \bf:
>
> xlabel('$\textbf{toto}$') # bad
> xlabel(r'$\textbf{toto}$') # ok
> xlabel('$\bf{toto}$') # bad
> xlabel(r'$\bf{toto}$') # ok
>
> And this bring to the second question, I would like to create the xlabel
> with latex stuf inside somewhere in my script:
>
> label='$\textrm{test}_2$'
>
> but that can't work:
>
>
> How to tell that I want the "r" before the chains to have TeX working
> like expected?

I think you have much to gain and nothing to lose by *always* using raw
are escape sequences; in an ordinary string, without the leading r, the
two-character sequences are translated into control characters (bell and
tab, respectively). \i is not an escape sequence, so it gets left alone.

Eric

humufr@...136... wrote:

I tried:

label='$\textrm{test}_2$
xlabel(r label)
xlabel(r+label)

etc but it not working (like I expected). So I would like to know if there are a way to precise that the text is a raw string by another thing that the r character just before the string. Perhaps that will be good to have an option like raw=true or something similar?

There is no such thing as a raw string *object*. There are only raw string *literals*. The r'' determines how the source code is parsed, not how the contents of the object is treated.

label = r'$\textrm{test}_2$'
xlabel(label)

After the source code containing the string literal is parsed, the string is simply a string.

···

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
an underlying truth."
-- Umberto Eco

Thank you very much I didn't know this. That will be very helpful.

N.

···

Le Mardi 31 Octobre 2006 23:47, Robert Kern a écrit :

humufr@...136... wrote:
> I tried:
>
> label='$\textrm{test}_2$
> xlabel(r label)
> xlabel(r+label)
>
> etc but it not working (like I expected). So I would like to know if
> there are a way to precise that the text is a raw string by another thing
> that the r character just before the string. Perhaps that will be good to
> have an option like raw=true or something similar?

There is no such thing as a raw string *object*. There are only raw string
*literals*. The r'' determines how the source code is parsed, not how the
contents of the object is treated.

label = r'$\textrm{test}_2$'
xlabel(label)

After the source code containing the string literal is parsed, the string
is simply a string.