Computer Modern Glyph Error #17007

Activity

1. anntzer commented on Apr 2, 2020

   

   anntzer

   on Apr 2, 2020

   Contributor

   More actions

   Likely due to #14567? Seems reasonable to special case unicode minus to map to normal minus given that we already special case it for other purposes and also #16366, just needs to figure out what are the fonts that need that and can also do it correctly (not mapping to a dash).
2. anntzer

   added

   topic: text/fonts

   on Apr 2, 2020
3. anntzer commented on Apr 3, 2020

   

   anntzer

   on Apr 3, 2020

   Last edited by anntzer

   Contributor

   More actions

   Ah, actually that's not a regression, the unicode minus comes from

   matplotlib/lib/matplotlib/mathtext.py

   Line 63 in bb75f73

   # From UTF #25: U+2212 minus sign is the preferred

   (of course we can still fix it...).

   I'm extremely confused as to why using cmr causes an warning in a StixFonts instance, though (as can be checked by breakpoint()ing at the warning position) :/
4. anntzer

   added

   topic: text/mathtext

   on Apr 3, 2020
5. roussel-ryan commented on Apr 3, 2020

   

   roussel-ryan

   on Apr 3, 2020

   Author

   More actions

   Ok thank you for the effort! I'm not sure if I can do anything to help, but please let me know if there is
6. casperdcl commented on Jul 5, 2020

   

   casperdcl

   on Jul 5, 2020

   Contributor

   More actions

   Same issue here.

   Setting font as Computer Modern Roman (matplotlib.rcParams.update({'font.family': 'cmr10'})) results in negative signs in ticklabels not rendering. Oddly, negative signs in titles & labels render fine.

   

   Code for reproduction

   Details

   import matplotlib
   matplotlib.rcParams.update({
       #'mathtext.fontset': 'cm',
       'font.family': 'cmr10'
   })
   import matplotlib.pyplot as plt
   
   plt.figure()
   plt.plot(range(-1, 1), range(-1, 1))
   plt.title(r"dash (-) $mathtext:negative (-)\bf{mathtext.bf:negative (-)}$")
   plt.xlabel(r"dash (-) $mathtext:negative (-)\bf{mathtext.bf:negative (-)}$")
7. tacaswell

   added this to the v3.4.0 milestone on Jul 7, 2020
8. casperdcl commented on Sep 2, 2020

   

   casperdcl

   on Sep 2, 2020

   Last edited by casperdcl

   Contributor

   More actions

   unfortunately the only workaround I could come up with is:

   plt.gca().set_xticklabels([i.get_text().replace('−', '$-$') for i in ax.get_xticklabels()])
   plt.gca().set_yticklabels([i.get_text().replace('−', '$-$') for i in ax.get_yticklabels()])

   which is annoying since 'font.family': ('cmr10', 'STIXGeneral') should really work.
9. anntzer commented on Sep 2, 2020

   

   anntzer

   on Sep 2, 2020

   Last edited by anntzer

   Contributor

   More actions

   I looked a bit more into this. Fundamentally, the problem is that we are relying on the old computer modern fonts, where symbols (e.g. minus) and letters/digits are in different font files (cmr10/cmsy10); moreover the "standard" (non-mathtext) Text object is only able to use a single font file at a time (and it would be quite a big surgery to change that limitation).

   Fortunately, when using mathtext, you can use multiple fonts at the same time; so one needs to force the ticks to use mathtext with rcParams["axes.formatter.use_mathtext"] = True, and then we're not done yet, because the ticker uses \mathdefault to wrap ticks, i.e. use the "non-mathtext" font... so then we need to add a special-case to mathtext, when using cmr10 as the non-mathtext font, to look up the minus sign in cmsy10 instead:

   diff --git i/lib/matplotlib/mathtext.py w/lib/matplotlib/mathtext.py
   index 8b9df7e19..8fdc29cad 100644
   --- i/lib/matplotlib/mathtext.py
   +++ w/lib/matplotlib/mathtext.py
   @@ -842,6 +842,10 @@ class UnicodeFonts(TruetypeFonts):
                found_symbol = False
                font = self._get_font(new_fontname)
                if font is not None:
   +                if font.family_name == "cmr10" and uniindex == 0x2212:
   +                    font = get_font(
   +                        cbook._get_data_path("fonts/ttf/cmsy10.ttf"))
   +                    uniindex = 0xa1
                    glyphindex = font.get_char_index(uniindex)
                    if glyphindex != 0:
                        found_symbol = True

   (probably a real patch would need to add a comment there). Together with rcParams["axes.formatter.use_mathtext"] = True, I think this is the only reasonable short-term fix. Brownie points for whoever makes a PR out of this.

   Long term I would like to get rid of the numerous cmXX10 fonts and replace them by the monolithic Latin Modern Math font, which should avoid all these problems. I guess that the cmr fonts shipped by Matplotlib should not be considered as "usable" for anything else than rcParams["mathtext.fontset"] = "cm" (using them for font.family will cause lots of trouble, like here); if you want to use CM for regular text consider just downloading Latin Modern Math (for example) and using that.

   👍React with 👍1Reacted by Casper da Costa-Luis
10. casperdcl

    added a commit that references this issue on Sep 2, 2020

    fix cmr10 negative sign in cmsy10

    ...

    This issue will close once commit a77f18d is merged into the 'master' branch.

    a77f18d
11. anntzer

    changed the title [-]Computer Modern Glypth Error[/-] [+]Computer Modern Glyph Error[/+] on Sep 3, 2020
12. ehremington commented on Sep 14, 2020

    

    ehremington

    on Sep 14, 2020

    Last edited by ehremington

    More actions

    This also happens with the xkcd plotting style using the "Humor Sans" font.

    x = np.linspace(0,10,20)
    y = 2*x-3
    
    with plt.xkcd():
        fig = plt.figure()
        ax = fig.add_subplot()
        ax.plot(x,y)
    

    👍React with 👍1Reacted by hannah
13. adiazmont commented on Sep 21, 2020

    

    adiazmont

    on Sep 21, 2020

    More actions

    I was able to get rid of the RuntimeWarning by declaring the font usage with:

    plt.rcParams["font.serif"] = "cmr10"

    Hence:

    import matplotlib.pyplot as plt
    plt.rcParams["font.serif"] = "cmr10"
    fig, ax = plt.subplots()
    
    ax.set_title('This is a special font:')
    ax.set_xlabel(r'This is the default font $\alpha\beta\gamma$')
    ax.set_yticks([-1, 0, 1])
    plt.show()
    

    

    And, it continues to work despite the declaration of the yticks, as in:

    import numpy as np
    import matplotlib.pyplot as plt
    plt.rcParams["font.serif"] = "cmr10"
    fig, ax = plt.subplots()
    
    ax.set_title('This is a special font:')
    ax.set_xlabel(r'This is the default font $\alpha\beta\gamma$')
    ax.set_yticks(np.arange(-1, 1.25, 0.25))
    plt.show()
    

    

    Hope this helps!

    👍React with 👍1Reacted by Sirawit Butmaratthaya
14. jonas-eschle commented on Nov 10, 2020

    

    jonas-eschle

    on Nov 10, 2020

    Contributor

    More actions

    Are there any news on this?

    👍React with 👍1Reacted by Michael B. Currie
15. casperdcl

    added a commit that references this issue on Nov 10, 2020

    fix cmr10 negative sign in cmsy10

    ...

    This issue will close once commit f8a31a0 is merged into the 'master' branch.

    f8a31a0
16. casperdcl commented on Nov 10, 2020

    

    casperdcl

    on Nov 10, 2020

    Contributor

    More actions

    just rebased #18397
17. QuLogic

    modified the milestones: v3.4.0, v3.5.0 on Jan 27, 2021
18. casperdcl

    added a commit that references this issue on Apr 23, 2021

    fix cmr10 negative sign in cmsy10

    ...

    This issue will close once commit 71ea0cd is merged into the 'master' branch.

    71ea0cd
19. tacaswell

    closed this as completedin #18397on May 14, 2021
20. jklymak

    added a commit that references this issue on Jun 13, 2021

    fix cmr10 negative sign in cmsy10

    ...

    This issue will close once commit 28ea44a is merged into the 'placeholder' branch.

    28ea44a
21. story645 commented on Oct 31, 2023

    

    story645

    on Oct 31, 2023

    Last edited by story645

    Member

    More actions

    This also happens with the xkcd plotting style using the "Humor Sans" font.

    So uh, this is why #26854 is failing (the plt.xkcd examples seem to work because they don't have a negative in the labels anywhere): throws "glyph missing" warning for title, omits hyphen for ticks: