Hi all,
Firstly, I love your software. It's great and largely it Just Works.
However, I came across some weirdness pretty quickly also, without
having to do anything particularly unusual.
I wrote some code to generate a pair of lists about 300 elements long,
and plotted them. I found that the line plot didn't have all the data
points connected.
When I saved to SVG, the output was correct.
Also, when I tried to perform a scatter plot, I got runtime errors and
no plot was drawn. These problems occur 100% of the time on my machine
with my test files.
I'm not sure if this list accepts files or not, but I am happy to
provide the code and sample files which demonstrate this error, and/or
respond to the bugfixing process.
Cheers,
-Tennessee
Tennessee,
Maybe I missed it, but I did not see any reply to your message. We welcome simple scripts that expose bugs--and the simpler the better. If something more than a simple script is required, then instead of sending a big file to the list, you could put it on an ftp server if you have access to one, or send it to one of us off-list upon request.
Tennessee Leeuwenburg wrote:
[...]
I wrote some code to generate a pair of lists about 300 elements long,
and plotted them. I found that the line plot didn't have all the data
points connected.
What backend were you using, and what operating system? What mpl version? Was the lack of connectedness at the level of a missing pixel, or was a whole line segment missing?
When I saved to SVG, the output was correct.
So it sounds like it must be a problem with a particular backend.
Also, when I tried to perform a scatter plot, I got runtime errors and
no plot was drawn. These problems occur 100% of the time on my machine
with my test files.
Until a recent change in SVN, scatter required an array, not a list, for its colors argument. Could this be the problem in your case?
I'm not sure if this list accepts files or not, but I am happy to
provide the code and sample files which demonstrate this error, and/or
respond to the bugfixing process.
Eric
I've sent Eric the files off-list. Anyone else who wants them, let me
know. The bundle is about 400Kb -- not huge but not tiny. The script
itself is small, it's just the data file and the output images which
take up the space.
The .png and onscreen renderer are both missing line segments, and
behave in the same way. The .svg renderer behaves as expected.
I'm running a very up-to-date linux, and I installed matplotlib newly
about 4 days ago.
Cheers,
-T
Tennessee Leeuwenburg wrote:
I've sent Eric the files off-list. Anyone else who wants them, let me
know. The bundle is about 400Kb -- not huge but not tiny. The script
itself is small, it's just the data file and the output images which
take up the space.
The .png and onscreen renderer are both missing line segments, and
behave in the same way. The .svg renderer behaves as expected.
I'm running a very up-to-date linux, and I installed matplotlib newly
about 4 days ago.
Cheers,
-T
Tennessee,
The first thing I notice is that you are trying to plot with log-log scales, but some of your y values are zero. Log(0) is undefined. The Agg renderers are doing something sensible: leaving out the 0 values. It is actually the ps and svg renderers that are incorrect, in that they seem to be substituting a value of 1 for each zero; they are bridging what *should* be gaps.
Eric
That could certainly explain it.
I don't know that I agree that it's correct -- I'm not graphing log(X),
I'm graphing X, and 0 is a valid value for it. Only the scale is
logarithmic, but it still contains a 0. I'll bow to a more expert
opinion if there's disagreement.
Cheers,
-T
ยทยทยท
On Mon, 2006-03-13 at 20:08 -1000, Eric Firing wrote:
Tennessee Leeuwenburg wrote:
> I've sent Eric the files off-list. Anyone else who wants them, let me
> know. The bundle is about 400Kb -- not huge but not tiny. The script
> itself is small, it's just the data file and the output images which
> take up the space.
>
> The .png and onscreen renderer are both missing line segments, and
> behave in the same way. The .svg renderer behaves as expected.
>
> I'm running a very up-to-date linux, and I installed matplotlib newly
> about 4 days ago.
>
> Cheers,
> -T
Tennessee,
The first thing I notice is that you are trying to plot with log-log
scales, but some of your y values are zero. Log(0) is undefined. The
Agg renderers are doing something sensible: leaving out the 0 values.
It is actually the ps and svg renderers that are incorrect, in that they
seem to be substituting a value of 1 for each zero; they are bridging
what *should* be gaps.
Eric