Re: [Matplotlib-users] saving data to a file
belinda thom wrote:
> Hi,
>
> Is there a way for me to keep adding the next row of a 2d array to a
> file via load? (matlab's save had a very useful -append option).
>
> I managed to get 2d laod/save working, e.g.
>
>import numpy as N
>import pylab as P
>import bthom.utils as U
># a numpy 2d array
>a = N.arange(12,dtype=N.float).reshape((3,4))
>a[0][0] = N.pi
># checking out the matploblib save/load stuff
>P.save("data.csv", a, fmt="%.4f", delimiter=";")
>aa = P.load("data.csv", delimiter= ";")
>x,y,z,w = P.load("data.csv", delimiter=";", unpack=True)
>
> The above took me longer than it perhaps should have b/c of advice
> I'd gotten elsewhere recommending trying to keep numpy and pylab
> separate when possible (to take advantage of all of numpy's features;
> it seems numpy doesn't even have the all-to-handy load/save
> functionality).
>
> When I try similar tricks to write one row at a time, I'm hosed in
> that the shape is gone:
>
># checking out a way to keep appending
>fname = "data1.csv"
>U.clobber_file(fname) #this thing just ensures 0 bytes in file
>f = open(fname,"a")
>nrows,ncols = a.shape
>for i in range(nrows) :
>P.save(f, a[i,:], fmt="%d", delimiter=";")
>f.close()
>aaa = P.load("data1.csv", delimiter= ";")
>
> in particular:
>
>% cat data1.csv
>3
>1
>2
>4
>
>11
>
> Thanks in advance,
> --b
>
This is because pylab.save() writes every 1D-array (like a[i,:]) as
"column vector". In the definition of the save() function:
[...]
if len(X.shape)==1:
origShape = X.shape
X.shape = len(X), 1
[...]
This reshapes the 1D-array (len(a[i,:].shape) == 1) to a 2D-array of
shape Nx1 and a loop over the first axis writes the rows (in this case
one element per row) to file.
There are several ways to do what you want:
#---#
# generate data
a = N.arange(12,dtype=N.float).reshape((3,4))
a[0][0] = N.pi
P.save("data.csv", a, fmt="%.4f", delimiter=";")
# (A)
# rather hackish way, define your own save(), not
# really useful, just to show that it works
def save2(fname, X, fmt='%.18e',delimiter=' '):
if is_string_like(fname):
if fname.endswith('.gz'):
import gzip
fh = gzip.open(fname,'wb')
else:
fh = file(fname,'w')
elif hasattr(fname, 'seek'):
fh = fname
else:
raise ValueError('fname must be a string or file handle')
X = N.asarray(X)
origShape = None
if len(X.shape)==1:
origShape = X.shape
# >
##X.shape = len(X), 1
X.shape = 1, len(X)
# <
for row in X:
fh.write(delimiter.join([fmt%val for val in row]) + '\n')
if origShape is not None:
X.shape = origShape
fname = "data1.csv"
f = open(fname,"a")
nrows,ncols = a.shape
for i in range(nrows) :
save2(f, a[i,:], fmt="%f", delimiter=";")
f.close()
aaa = P.load("data1.csv", delimiter= ";")
print aaa
print "---"
# (B)
# do it without a save() function
fname = "data2.csv"
f = open(fname,"a")
nrows,ncols = a.shape
delim = ';'
fmt = '%f'
for i in range(nrows):
# just like in pylab.save()
f.write(delim.join([fmt %val for val in a[i,:]]) + '\n')
f.close()
aaa = P.load("data2.csv", delimiter= ";")
print aaa
print "---"
# (C)
# probably the best: save a 1xn "row vector" per line
fname = "data3.csv"
f = open(fname,"a")
nrows,ncols = a.shape
for i in range(nrows) :
P.save(f, a[i,:].reshape((1,ncols)), fmt="%f", delimiter=";")
f.close()
aaa = P.load("data3.csv", delimiter= ";")
print aaa
HTH
--
cheers,
steve
Random number generation is the art of producing pure gibberish as
quickly as possible.
-
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] title and colorbar size
Eric, John - thanks for your tips, it works! petr On Tue, 2007-01-02 at 21:01, Eric Firing wrote: > John Hunter wrote: > Examples of the shrink kwarg are examples/image_masked.py and > examples/contour_demo.py. > > As an alternative to using the shrink kwarg you can always specify axes > positions manually. One example is in examples/multi_image.py. > Attached is another example modified from image_masked.py. > > I have added a bit to the docstring to emphasize the function of the > shrink kwarg. This will usually be the easiest manual solution to the > problem. I have also thought a bit about adding functionality to the > axes.draw() method that would allow the colorbar height to track the > height of the mappable axes object; maybe I will try it later. > pro-scan.png Description: PNG image - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
[Matplotlib-users] Complex Plot
Hi all, First of all, best wishes for the brand new year! I hope that 2007 will be a great year for all of you. Attached to this mail, there is an image representing a 'complex plot'. this is complex because it contains a lot of information (plot + table below the plot). I think the plot + table is not so difficult to do using matplotlib (the example table_demo.py should give an idea of the solution). What is, in my opinion more is: - the fact that the plot contains 6 vertical axis (three on the left and three on the right). - the legend is above the plot and is composed of color boxes that refer to a given axis and line on the plot. Do you think it is possible to do such a plot in matplotlib? Thanks in advance for any kind of help and thanks again for the matplotlib library! Best regards. Benoit -- Dr. Benoit Donnet Université Catholique de Louvain (UCL) Faculté des Sciences Appliquées - Département d'Ingénierie Informatique (INGI) Place Sainte Barbe, 2 1348 Louvain-la-Neuve Belgium Phone: +32 10 47 87 18 Home page: http://www.info.ucl.ac.be/~donnet - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Complex Plot
> "Benoit" == Benoit Donnet <[EMAIL PROTECTED]> writes: Benoit> Do you think it is possible to do such a plot in Benoit> matplotlib? Hey Benoit -- thanks for posting that image. It's good to get some reminders of the current limitations of mpl so we can focus on improving them. There are two things in that plot that mpl cannot currently do. 1) multiple y-scales on the left and right. mpl supports a left and right scale (see examples/two_scale.py) but nothing like an arbitrary number of scales with arbitrary positioning as you see in the plot you attached. This has long been on the wish list (and is on the goals web page) but has not yet been implemented. This is something chaco does quite well because it is very common to make these plots in geophysics. For me it is one of the few remaining must-have features for matplotlib 1.0. You could hack your own scales using matplotlib lines and text instances. Indeed it wouldn't be too hard and if I get some time I'll do a demo which may serve as a prototype for refactoring the mpl axis code. 2) the horizontal legend layout - matplotlib is not very flexible in the legend layout and supports only vertical legends. This would be a nice feature. Currently the legend code can best be described as hairy, which is why few want to try to improve it. As for the text table at the bottom, you could either do this with table, probably your best choice, or with a series of side-by-side axes, or with some custom rectangles and text instances. We've talked before that it would be nice to have a layout engine, much like the gtk hbox and vbox, and this would be a good candidate for it. JDH - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Resolution of SVG output
This should help you understand dpi, font-size, etc. http://www.scipy.org/Cookbook/Matplotlib/AdjustingImageSize However, I'm not sure how imshow() and SVG work together -- SVG is just that -- "Scalable", it doesn't have a set resolution, and I don't know what happens when you embed a raster graphic in it -- can someone offer an explanation of what MPL does with imshow and SVG? -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R(206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [EMAIL PROTECTED] - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] numpy and matplotlib usage
Fernando and Eric have offered very nice explanations, but I have one thing to add: Fernando Perez wrote: > hopefully the responsibilities will be: > > - ipython -> interactive work > - numpy/scipy -> numerics > - matploblib -> plotting I sure hope so too. > Following these ideas, in my personal use I normally do: > > import numpy as N > import scipy as S > import pylab as P I do something very similar - I really believe in namespaces, "import *" is a "bad idea". However, I also try to avoid pylab altogether, in favor of: import matplotlib as MPL, MPL.PlottingStuff() matplotlib provides the plotting functionality in a nice OO way. pylab is essentially a wrapper that provides a Matlab-like procedural interface to matplotlib. For me, one of the reasons I use python, rather than Matlab is that it is a richer, more feature-full language, including OO. Some folks think the procedural approach is better for interactive use, but I'm not so sure, and I'm quite sure that the OO approach is better for "real programs" At this point, it isn't quite possible to use just matplotlib for interactive use, as pylab has the functionality to manage the figure windows, etc, so I do use a tiny bit of pylab there, but try to keep to the OO interface otherwise. THe key stumbling block is docs -- most of the docs and tutorials use the pylab interface, so it's a bit harder to figure out what to do. This should help get you started: http://sourceforge.net/mailarchive/message.php?msg_id=11033442 (Did that ever get up on the Wiki?, and/or does anyone have other pointers?) -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R(206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [EMAIL PROTECTED] - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
[Matplotlib-users] How can I set the backgroundcolor of text with set_backgroundcolor ?
Hello -
I want to set the backgroundcolor of text with the set_backgroundcolor
function.
Does that actually work?
I saw a more complicated way to do it by defining a bbox, but this would be
much easier (if I got it to work).
Here's my example that doesn't work.
Thanks for any suggestions,
Mark
from pylab import *
plot([1,2,3])
t = text(1,2,'Hello')
t.set_backgroundcolor('r')
draw()
-
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How can I set the backgroundcolor of text with set_backgroundcolor ?
> "Mark" == Mark Bakker <[EMAIL PROTECTED]> writes: Mark> Hello - I want to set the backgroundcolor of text with the Mark> set_backgroundcolor function. Does that actually work? I Mark> saw a more complicated way to do it by defining a bbox, but Mark> this would be much easier (if I got it to work). Here's my Mark> example that doesn't work. Thanks for any suggestions, Strange. When I saw your post my first thought was "hmmm, I didn't know we had a text background color". I looked through the text.py code and it is there as a property, but is totally unused. I don't know who added it, but apparently someone got interrupted mid-code. That someone could be me, but if anyone knows where this came from speak up; otherwise it will be removed. The bbox is the standard way to do this, and is a bit more general since you can set the alpha, the linewidth, the edgecolor, etc... ax.text(1,2,'hi mom', bbox=dict(facecolor='red')) JDH - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How can I set the backgroundcolor of text with set_backgroundcolor ?
Thanks John. This works great. I think, however, that set_backgroundcolor would be useful. It should be easy to fix. If nobody speaks up, I will take a crack at it, Mark On 1/3/07, John Hunter <[EMAIL PROTECTED]> wrote: > "Mark" == Mark Bakker <[EMAIL PROTECTED]> writes: Mark> Hello - I want to set the backgroundcolor of text with the Mark> set_backgroundcolor function. Does that actually work? I Mark> saw a more complicated way to do it by defining a bbox, but Mark> this would be much easier (if I got it to work). Here's my Mark> example that doesn't work. Thanks for any suggestions, Strange. When I saw your post my first thought was "hmmm, I didn't know we had a text background color". I looked through the text.py code and it is there as a property, but is totally unused. I don't know who added it, but apparently someone got interrupted mid-code. That someone could be me, but if anyone knows where this came from speak up; otherwise it will be removed. The bbox is the standard way to do this, and is a bit more general since you can set the alpha, the linewidth, the edgecolor, etc... ax.text(1,2,'hi mom', bbox=dict(facecolor='red')) JDH - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How can I set the backgroundcolor of text with set_backgroundcolor ?
> "Mark" == Mark Bakker <[EMAIL PROTECTED]> writes: Mark> Thanks John. This works great. I think, however, that Mark> set_backgroundcolor would be useful. It should be easy to Mark> fix. If nobody speaks up, I will take a crack at it, Mark What do you have in mind, a simple convenience function that does def set_backgroundcolor(self, color): """ Set the background color of the text by updating the bbox facecolor ACCEPTS: any matplotlib color """ if self._bbox is None: self._bbox = dict(facecolor=color, edgecolor=color) else: self._bbox.update(dict(facecolor=color)) I'm not too opposed to it, but it does violate the maxim "There should be one-- and preferably only one --obvious way to do it." Of course, we violate this throughout mpl offerings lots of convenience functions, but it is something to bear in mind. - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How can I set the backgroundcolor of text with set_backgroundcolor ?
Thanks for writing the convenience function John ! I think there is a large group (like the students in my class) who use matplotlib as a simple tool to make beautiful graphs. To compete with matlab we need to keep simple tasks simple. I personally think that this convenience function is a good one to add. Probably under pylab. Anybody else want to weigh in? Mark On 1/3/07, John Hunter <[EMAIL PROTECTED]> wrote: > "Mark" == Mark Bakker <[EMAIL PROTECTED]> writes: Mark> Thanks John. This works great. I think, however, that Mark> set_backgroundcolor would be useful. It should be easy to Mark> fix. If nobody speaks up, I will take a crack at it, Mark What do you have in mind, a simple convenience function that does def set_backgroundcolor(self, color): """ Set the background color of the text by updating the bbox facecolor ACCEPTS: any matplotlib color """ if self._bbox is None: self._bbox = dict(facecolor=color, edgecolor=color) else: self._bbox.update(dict(facecolor=color)) I'm not too opposed to it, but it does violate the maxim "There should be one-- and preferably only one --obvious way to do it." Of course, we violate this throughout mpl offerings lots of convenience functions, but it is something to bear in mind. - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
[Matplotlib-users] Using 'scaled' for aspect ratio
The enhanced way of handling aspect ratios that Eric implemented works
great.
There is, however, one change from the old implementation that I don't like.
In the old implementation, when setting axis('scaled') it also turned
autoscale off.
This makes sense (and I used it a lot). It means that you can set the
axis('scaled'), which means the aspect ratios are set equal and the axis
limits are not changed, at any point when you like the data limits. The axis
limits are then fixed so that every time you add something else to the
figure it will keep these limits.
In the new implementation (ok, it has been there for a little while now),
you have to give a separate set_autoscale_on(False) command.
Besides the odd name of the function (you actually turn the autoscale off),
it is a command that should be set right away by axis('scaled'). If you want
the autoscale to remain on, you should use axis('equal')
Anybody else an opinion? Andrea?
Thanks, Mark
-
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Using 'scaled' for aspect ratio
Mark Bakker wrote:
> The enhanced way of handling aspect ratios that Eric implemented works
> great.
> There is, however, one change from the old implementation that I don't like.
>
> In the old implementation, when setting axis('scaled') it also turned
> autoscale off.
> This makes sense (and I used it a lot). It means that you can set the
> axis('scaled'), which means the aspect ratios are set equal and the axis
> limits are not changed, at any point when you like the data limits. The
> axis limits are then fixed so that every time you add something else to
> the figure it will keep these limits.
>
> In the new implementation (ok, it has been there for a little while
> now), you have to give a separate set_autoscale_on(False) command.
> Besides the odd name of the function (you actually turn the autoscale
> off), it is a command that should be set right away by axis('scaled').
> If you want the autoscale to remain on, you should use axis('equal')
Here is the present code fragment (slightly mangled by the mailer):
elif s in ('equal', 'tight', 'scaled', 'normal', 'auto',
'image'):
self.set_autoscale_on(True)
self.set_aspect('auto')
self.autoscale_view()
self.apply_aspect()
if s=='equal':
self.set_aspect('equal', adjustable='datalim')
elif s == 'scaled':
self.set_aspect('equal', adjustable='box', anchor='C')
elif s=='tight':
self.autoscale_view(tight=True)
self.set_autoscale_on(False)
elif s == 'image':
self.autoscale_view(tight=True)
self.set_autoscale_on(False)
self.set_aspect('equal', adjustable='box', anchor='C')
At present, the difference between "equal" and "scaled" is not the
autoscale state but the "adjustable".
I don't have any objection to changing the behavior of "scaled" as you
suggest, if that is what people want. Alternatively, yet another word
could be used to define the behavior you want, and that behavior could
be added. I don't find "scaled" or "equal" very descriptive or
intuitive; nor do I find that either word suggests how autoscale should
be set. (And I agree, "set_autoscale_on(False)" is ugly.)
Eric
-
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
