Re: [Matplotlib-users] color in plot3d
Thanks again! El 17/06/10 02:03, Mike Alger escribió: Pablo, I found the example on the svn http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/trunk/matplotlib/examples/mplot3d/surface3d_demo3.py?view=log it will demonstrate the face colour thing but personally I found getting the rgb tuple data into an array a bit too complicated for my needs. Regarding that little SNAFU about the matrix size, I was half asleep and in a rush when I wrote the reply to your email, so I knew if I made a mistake it was in the interpretation there :D A slice, reshape function may be more efficient/ easier to read but I took the loop structure right from the plot surface command to make sure it was done exactly the same way as the 3d surface. It may be interesting to see which is more efficient computationally and see if there is an improvement to be made in the plot surface command *From:* Pablo Angulo [mailto:pablo.ang...@uam.es] *Sent:* June-16-10 9:07 AM *To:* Mike Alger *Cc:* matplotlib-users@lists.sourceforge.net *Subject:* Re: [Matplotlib-users] color in plot3d El 15/06/10 01:22, Mike Alger escribió: The way that color keyword is set up, it is dedsigned to take a color word or rgba tuple , (Reinier will know this better than me), however if you want to just assign colors based on a colour map you can take you color array and reshape the same way the plot surface command does then use surf.set_array() If I understand you correctly, you mean there is a way to use directly a map from two or three spatial coordinates into the three or four components of the color space? That's interesting. It might be limiting that this map has to factor as the composition of an scalar map and a color map, even for 2d plots. here is a snippet of the code I use to do this I am pretty sure it won’t run the way it is right now but the idea is buried in there Thanks, I got the idea! note that regmap xyz and costmapz are all the same size and are nxm matrices costmapout is a 2x(m.n) if i can do the math correctly One comment: from your code it seems that costmapout is a 1D array of lenght roughly equal (m*n)/scale**2 with the data coming from costmapz. Why don't you use a slice followed by a reshape command? No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.829 / Virus Database: 271.1.1/2942 - Release Date: 06/16/10 14:35:00 -- ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] color in plot3d
El 15/06/10 01:22, Mike Alger escribió: The way that color keyword is set up, it is dedsigned to take a color word or rgba tuple , (Reinier will know this better than me), however if you want to just assign colors based on a colour map you can take you color array and reshape the same way the plot surface command does then use surf.set_array() If I understand you correctly, you mean there is a way to use directly a map from two or three spatial coordinates into the three or four components of the color space? That's interesting. It might be limiting that this map has to factor as the composition of an scalar map and a color map, even for 2d plots. here is a snippet of the code I use to do this I am pretty sure it won’t run the way it is right now but the idea is buried in there Thanks, I got the idea! note that regmap xyz and costmapz are all the same size and are nxm matrices costmapout is a 2x(m.n) if i can do the math correctly One comment: from your code it seems that costmapout is a 1D array of lenght roughly equal (m*n)/scale**2 with the data coming from costmapz. Why don't you use a slice followed by a reshape command? subcostmapz= costmapz[0::scale,0::scale] costmapout = subcostmapz.reshape(subcostmapz.size) scale= 3 ... rows, cols = costMAPz.shape costmapout = [] for rs in np.arange(0, rows-1, scale): for cs in np.arange(0, cols-1, scale): costmapout.append(costMAPz[rs][cs]) costmapout=np.array(costmapout) -- ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] color in plot3d
Pablo, I found the example on the svn http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/trunk/matplotlib/examples/mplot3d/surface3d_demo3.py?view=log http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/trunk/matplotlib/examples/mplot3d/surface3d_demo3.py?view=log it will demonstrate the face colour thing but personally I found getting the rgb tuple data into an array a bit too complicated for my needs. Regarding that little SNAFU about the matrix size, I was half asleep and in a rush when I wrote the reply to your email, so I knew if I made a mistake it was in the interpretation there :D A slice, reshape function may be more efficient/ easier to read but I took the loop structure right from the plot surface command to make sure it was done exactly the same way as the 3d surface. It may be interesting to see which is more efficient computationally and see if there is an improvement to be made in the plot surface command From: Pablo Angulo [mailto:pablo.ang...@uam.es] Sent: June-16-10 9:07 AM To: Mike Alger Cc: matplotlib-users@lists.sourceforge.net Subject: Re: [Matplotlib-users] color in plot3d El 15/06/10 01:22, Mike Alger escribió: The way that color keyword is set up, it is dedsigned to take a color word or rgba tuple , (Reinier will know this better than me), however if you want to just assign colors based on a colour map you can take you color array and reshape the same way the plot surface command does then use surf.set_array() If I understand you correctly, you mean there is a way to use directly a map from two or three spatial coordinates into the three or four components of the color space? That's interesting. It might be limiting that this map has to factor as the composition of an scalar map and a color map, even for 2d plots. here is a snippet of the code I use to do this I am pretty sure it won’t run the way it is right now but the idea is buried in there Thanks, I got the idea! note that regmap xyz and costmapz are all the same size and are nxm matrices costmapout is a 2x(m.n) if i can do the math correctly One comment: from your code it seems that costmapout is a 1D array of lenght roughly equal (m*n)/scale**2 with the data coming from costmapz. Why don't you use a slice followed by a reshape command? No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.829 / Virus Database: 271.1.1/2942 - Release Date: 06/16/10 14:35:00 -- ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] color in plot3d
First what version of mpl are you using? if it is recent this colour word
already exists, I asked about this a couple months ago and i should point you
first to the example in the svn it does a checkerboard, but i cannot remember
the exact name. Although i know it plots a checkerboard effect on one of the
example plots.
The way that color keyword is set up, it is dedsigned to take a color word or
rgba tuple , (Reinier will know this better than me), however if you want to
just assign colors based on a colour map you can take you color array and
reshape the same way the plot surface command does then use surf.set_array()
here is a snippet of the code I use to do this I am pretty sure it won’t run
the way it is right now but the idea is buried in there
note that regmap xyz and costmapz are all the same size and are nxm matrices
costmapout is a 2x(m.n) if i can do the math correctly
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
import numpy as np
#--
ax = Axes3D(fig)
scale= 3
surf = ax.plot_surface(regMAPx ,regMAPy,-regMAPz ,
rstride=scale,cstride=scale, cmap=cm.jet, linewidth=.250 )
# to reshape the cost map to match grid used in plot surf
rows, cols = costMAPz.shape
costmapout = []
for rs in np.arange(0, rows-1, scale):
for cs in np.arange(0, cols-1, scale):
costmapout.append(costMAPz[rs][cs])
costmapout=np.array(costmapout)
surf.set_array(costmapout)
## do your show plot stuff here!!
Mike Alger
From: Pablo Angulo [mailto:pablo.ang...@uam.es]
Sent: June-11-10 7:04 AM
To: matplotlib-users@lists.sourceforge.net
Subject: [Matplotlib-users] color in plot3d
Hello!
I wonder if there is a way to make 3d plots specifying arbitrary colors,
instead of having the color be a function of the height. I was able to achieve
this making minimal changes to the plot_surface method of Axes3D, adding as an
optional keyword argument a function cfun which specifies the color (it
specifies a real number that is mapped into a color by the color map cmap). But
is there a standard way?
Regard
Pablo Angulo
from matplotlib.colors import Normalize, colorConverter
def plot_surface(self, X, Y, Z, *args, **kwargs):
'''
Create a surface plot.
By default it will be colored in shades of a solid color,
but it also supports color mapping by supplying the *cmap*
argument.
==
ArgumentDescription
==
*X*, *Y*, Data values as numpy.arrays
*Z*
*rstride* Array row stride (step size)
*cstride* Array column stride (step size)
*color* Color of the surface patches
*cmap* A colormap for the surface patches.
*cfun* The function giving the color
==
'''
had_data = self.has_data()
rows, cols = Z.shape
tX, tY, tZ = np.transpose(X), np.transpose(Y), np.transpose(Z)
rstride = kwargs.pop('rstride', 10)
cstride = kwargs.pop('cstride', 10)
color = kwargs.pop('color', 'b')
color = np.array(colorConverter.to_rgba(color))
cmap = kwargs.get('cmap', None)
cfun = kwargs.pop('cfun', None)
polys = []
normals = []
avgz = []
if not cfun:
cfun = lambda p:p[2]
for rs in np.arange(0, rows-1, rstride):
for cs in np.arange(0, cols-1, cstride):
ps = []
corners = []
for a, ta in [(X, tX), (Y, tY), (Z, tZ)]:
ztop = a[rs][cs:min(cols, cs+cstride+1)]
zleft = ta[min(cols-1, cs+cstride)][rs:min(rows, rs+rstride+1)]
zbase = a[min(rows-1, rs+rstride)][cs:min(cols, cs+cstride+1):]
zbase = zbase[::-1]
zright = ta[cs][rs:min(rows, rs+rstride+1):]
zright = zright[::-1]
corners.append([ztop[0], ztop[-1], zbase[0], zbase[-1]])
z = np.concatenate((ztop, zleft, zbase, zright))
ps.append(z)
# The construction leaves the array with duplicate points, which
# are removed here.
ps = zip(*ps)
lastp = np.array([])
ps2 = []
avgzsum = 0.0
for p in ps:
if p != lastp:
ps2.append(p)
lastp = p
avgzsum += cfun(p)
polys.append(ps2)
avgz.append(avgzsum / len(ps2))
v1 = np.array(ps2[0]) - np.array(ps2[1])
v2 = np.array(ps2[2]) - np.array(ps2[0])
normals.append(np.cross(v1, v2))
polyc = art3d.Poly3DCollection(polys, *args, **kwargs)
if cmap is not None:
polyc.set_array(np.array(avgz))
polyc.set_linewidth(0
[Matplotlib-users] color in plot3d
Hello!
I wonder if there is a way to make 3d plots specifying arbitrary
colors, instead of having the color be a function of the height. I was
able to achieve this making minimal changes to the plot_surface method
of Axes3D, adding as an optional keyword argument a function *cfun*
which specifies the color (it specifies a real number that is mapped
into a color by the color map *cmap*). But is there a standard way?
Regard
Pablo Angulo
from matplotlib.colors import Normalize, colorConverter
def plot_surface(self, X, Y, Z, *args, **kwargs):
'''
Create a surface plot.
By default it will be colored in shades of a solid color,
but it also supports color mapping by supplying the *cmap*
argument.
==
ArgumentDescription
==
*X*, *Y*, Data values as numpy.arrays
*Z*
*rstride* Array row stride (step size)
*cstride* Array column stride (step size)
*color* Color of the surface patches
*cmap* A colormap for the surface patches.
*cfun* The function giving the color
==
'''
had_data = self.has_data()
rows, cols = Z.shape
tX, tY, tZ = np.transpose(X), np.transpose(Y), np.transpose(Z)
rstride = kwargs.pop('rstride', 10)
cstride = kwargs.pop('cstride', 10)
color = kwargs.pop('color', 'b')
color = np.array(colorConverter.to_rgba(color))
cmap = kwargs.get('cmap', None)
*cfun = kwargs.pop('cfun', None)*
polys = []
normals = []
avgz = []
*if not cfun:*
*cfun = lambda p:p[2]*
for rs in np.arange(0, rows-1, rstride):
for cs in np.arange(0, cols-1, cstride):
ps = []
corners = []
for a, ta in [(X, tX), (Y, tY), (Z, tZ)]:
ztop = a[rs][cs:min(cols, cs+cstride+1)]
zleft = ta[min(cols-1, cs+cstride)][rs:min(rows, rs+rstride+1)]
zbase = a[min(rows-1, rs+rstride)][cs:min(cols, cs+cstride+1):]
zbase = zbase[::-1]
zright = ta[cs][rs:min(rows, rs+rstride+1):]
zright = zright[::-1]
corners.append([ztop[0], ztop[-1], zbase[0], zbase[-1]])
z = np.concatenate((ztop, zleft, zbase, zright))
ps.append(z)
# The construction leaves the array with duplicate points, which
# are removed here.
ps = zip(*ps)
lastp = np.array([])
ps2 = []
avgzsum = 0.0
for p in ps:
if p != lastp:
ps2.append(p)
lastp = p
*avgzsum += cfun(p)*
polys.append(ps2)
avgz.append(avgzsum / len(ps2))
v1 = np.array(ps2[0]) - np.array(ps2[1])
v2 = np.array(ps2[2]) - np.array(ps2[0])
normals.append(np.cross(v1, v2))
polyc = art3d.Poly3DCollection(polys, *args, **kwargs)
if cmap is not None:
polyc.set_array(np.array(avgz))
polyc.set_linewidth(0)
else:
colors = self._shade_colors(color, normals)
polyc.set_facecolors(colors)
self.add_collection(polyc)
self.auto_scale_xyz(X, Y, Z, had_data)
return polyc
--
ThinkGeek and WIRED's GeekDad team up for the Ultimate
GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the
lucky parental unit. See the prize list and enter to win:
http://p.sf.net/sfu/thinkgeek-promo___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
