No fillalpha after eps export?

eps
opacity

asked 2013-02-06 13:51:53 +0100

pinwheel
51 ●3 ●3 ●7

updated 2015-01-14 10:36:53 +0100

FrédéricC

5311 ●4 ●44 ●118

Hey guys,

this is a slightly modified example from the sage help pages:

(plot(1+e^(-x^2), xmin=-2, xmax=2, ymin=0, ymax=2.5, fill=0.5, fillcolor='green', fillalpha=0.5)).save('t.eps')

It shows an exponential function which is filled from below by green color. The option fillalpha=0.5 should make this filling slightly transparent, which works perfectly when exporting to pdf, but repdroducably fails when exporting to eps. Is there any workaround?

edit retag flag offensive close merge delete

add a comment

2 Answers

Sort by » oldest newest most voted

answered 2013-02-06 17:30:33 +0100

fidbc

2423 ●4 ●26 ●61

Hi,

Not really a sage solution and far from optimal. You can try

sage: P=plot(1+e^(-x^2), xmin=-2, xmax=2, ymin=0, ymax=2.5, fill=0.5, fillcolor='green', fillalpha=0.5)
sage: P.save( 't.pdf')

And then

$ pdftops t.pdf
$ ps2eps t.ps

edit flag offensive delete link

Comments

Long story short, (e)ps does not properly support alpha. So, this is probably the best solution at present. There is no automatic way to make figures with alpha in (e)ps.

ppurka ( 2013-02-09 10:02:14 +0100 )edit

add a comment

answered 2013-02-06 20:54:45 +0100

kcrisman
12242 ●42 ●136 ●255

The problem is in our Polygon class - somehow it's not saving correctly. Compare these.

sage: polygon([(0,0), (1,1), (0,1)],alpha=.1).save('test.pdf')
sage: polygon([(0,0), (1,1), (0,1)],alpha=.1).save('test.eps')

If I can narrow it down a little more, I'll open a ticket. It's conceivable that it's a matplotlib issue, but I'd guess it's ours first.

edit flag offensive delete link

Comments

See http://trac.sagemath.org/sage_trac/ticket/14074 - my guess is still that we are doing something wrong, but it could be an mpl bug, in principle.

kcrisman ( 2013-02-06 21:11:59 +0100 )edit

I have updated the ticket after opening an upstream mpl bug https://github.com/matplotlib/matplotlib/issues/1740

ppurka ( 2013-02-08 04:11:36 +0100 )edit

And now matplotlib says this is actually not supported by ps.

kcrisman ( 2013-02-08 10:02:17 +0100 )edit

That is not correct. eps supports alpha channels. Here's proof: http://ompldr.org/vaGViZg/drawing.eps Ok. It is not so clear whether ps really really supports alpha. Some libraries use some tricks to get in some alpha support.

ppurka ( 2013-02-08 10:34:04 +0100 )edit

add a comment

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

No fillalpha after eps export?

2 Answers

Comments

Comments

Your Answer

Question Tools

Stats

Related questions

No fillalpha after eps export? edit

2 Answers

Comments

Comments

Your Answer

Question Tools

Stats

Related questions

No fillalpha after eps export?