[Matplotlib-users] saving data to a file
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
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[Matplotlib-users] load_demo.py
Hi, The documentation for pylab.load mentions the load_demo.py example. I can't find this on my distribution. I believe all Pylab examples live in site-packages/doc/matplotlib, for in there are files like log_demo.py (the only file that begins with load is load_converter.py, which is demonstrating using dates). Does anyone have access to load_demo.py or does it not exist (in which case the documentation for load should be modified)? Thanks, --b - 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
John Hunter wrote:
"Petr" == Petr Danecek <[EMAIL PROTECTED]> writes:
[...]
Petr> 2) When set_aspect() is used, the size of colorbar does not
Petr> respect y-dimension of the graph. (See the attached
Petr> example.) Is it possible to set the size of the colorbar
Petr> directly?
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.
One of the examples shows how to do this if I recall correctly, but I
don't remember which one. Eric Firing wrote it so I'm sure he'll be
along shortly to point you to the light. Eric -- perhaps we should
also add a snippet to the colorbar docstring since this is a common
request.
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.
Eric
#!/usr/bin/env python
'''imshow with masked array input and out-of-range colors.
'''
from pylab import *
import matplotlib.numerix.ma as ma
import matplotlib.colors as colors
delta = 0.025
x = y= arange(-3.0, 3.0, delta)
X, Y = meshgrid(x, y)
Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
Z = 10 * (Z2-Z1) # difference of Gaussians
# Set up a colormap:
palette = cm.gray
palette.set_over('r', 1.0)
palette.set_under('g', 1.0)
palette.set_bad('b', 1.0)
# Alternatively, we could use
# palette.set_bad(alpha = 0.0)
# to make the bad region transparent. This is the default.
# If you comment out all the palette.set* lines, you will see
# all the defaults; under and over will be colored with the
# first and last colors in the palette, respectively.
Zm = ma.masked_where(Z > 1.2, Z)
# By setting vmin and vmax in the norm, we establish the
# range to which the regular palette color scale is applied.
# Anything above that range is colored based on palette.set_over, etc.
fig = figure()
axi = fig.add_axes([0.1, 0.1, 0.7, 0.8])
im = axi.imshow(Zm, interpolation='bilinear',
cmap=palette,
norm = colors.Normalize(vmin = -1.0, vmax = 1.0, clip = False),
origin='lower', extent=[-3,3,-1,1])
title('Green=low, Red=high, Blue=bad')
axcb = fig.add_axes([0.85, 0.35, 0.02, 0.3])
fig.colorbar(im, cax=axcb, extend='both')
show()
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Re: [Matplotlib-users] title and colorbar size
> "Petr" == Petr Danecek <[EMAIL PROTECTED]> writes: Petr> Hello, i'd like to ask two questions: Petr> 1) Is it possible to control amount of space between title Petr> and graph? The y value of the title instance is in axes coordinates, so 1 is the top of the axes, and numbers greater than 1 are further above the top. So you can do t.set.y(1.1) where t is the matplotlib.text.Text instance returned from pylab 'title' or from matplotlib.axes.Axes.set_title (both do the same thing). Alternatively, you can set the title instance properties from the axes instance ax = fig.add_subplot(111) ax.title.set_y(1.1) Petr> 2) When set_aspect() is used, the size of colorbar does not Petr> respect y-dimension of the graph. (See the attached Petr> example.) Is it possible to set the size of the colorbar Petr> directly? One of the examples shows how to do this if I recall correctly, but I don't remember which one. Eric Firing wrote it so I'm sure he'll be along shortly to point you to the light. Eric -- perhaps we should also add a snippet to the colorbar docstring since this is a common request. 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] title and colorbar size
Petr Danecek wrote: > Hello, > i'd like to ask two questions: > > 1) Is it possible to control amount of space between title and graph? > Petr: The title command takes 'x' and 'y' keyword arguments that set the position of the title in axis coordinates. For example, try 'y=1.075' to move the title up a bit. > 2) When set_aspect() is used, the size of colorbar does not respect > y-dimension of the graph. (See the attached example.) Is it possible to > set the size of the colorbar directly? > I usually use the 'shrink' keyword to adjust the colorbar in situations like this. You have to fiddle with it a bit to get the right value. In your case, 'shrink=0.4' ought to do it. -Jeff -- Jeffrey S. Whitaker Phone : (303)497-6313 NOAA/OAR/CDC R/PSD1FAX : (303)497-6449 325 BroadwayBoulder, CO, USA 80305-3328 - 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] title and colorbar size
Hello,
i'd like to ask two questions:
1) Is it possible to control amount of space between title and graph?
2) When set_aspect() is used, the size of colorbar does not respect
y-dimension of the graph. (See the attached example.) Is it possible to
set the size of the colorbar directly?
Petr Danecek
test.png
Description: PNG image
from pylab import *
import os,sys,math
x = arange(0,2*pi,0.1)
y = arange(0,2*pi,0.1)
X, Y = meshgrid(x,y)
Z = sin(X)*sin(Y)
rc('figure',figsize=(3.346,3.346))
ax = subplot(111)
cs = ax.pcolor(X,Y,Z,shading='flat')
colorbar(cs)
title('Some title')
axis((0,2,0,1))
ax.set_aspect(1.0)
savefig('test.png',dpi=100)
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Re: [Matplotlib-users] IDLE, matplotlib and show command
I've seen that it also works with WxAgg version 2.8.0.1 for python 2.5 I hope this information can be useful Giorgio - 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
