matplotlib-users Mailing List for matplotlib

On 16-Jun-14 01:12, Eric Firing wrote:
> On 2014年06月15日, 12:17 PM, Virgil Stokes wrote:
>> There are some rather nice and useful matplotlib examples for colormaps
>> that are shown at:
>>
>> http://nbviewer.ipython.org/github/dpsanders/matplotlib-examples/blob/master/colorline.ipynb
>>
>> In*Example 1. Sine wave colored by time (uses the defaults for
>> colorline)*, how can one add a colorbar?
> lc = colorline(x, y)
> cbar = fig.colorbar(lc)
>
> Eric
>
>
This works fine --- thanks very much Eric.
Have a good day

On 16-Jun-14 00:46, Raymond Smith wrote:
> Hi Virgil,
>
> I did something very much like this recently by simply adding an axes 
> to my figure and using it to show a linspace of the data range off 
> which the line color was based. See 
> http://matplotlib.org/examples/color/colormaps_reference.html.
>
> Best,
> Ray
>
>
> On Sun, Jun 15, 2014 at 6:17 PM, Virgil Stokes <vs...@it... 
> <mailto:vs...@it...>> wrote:
>
> There are some rather nice and useful matplotlib examples for
> colormaps that are shown at:
>
> http://nbviewer.ipython.org/github/dpsanders/matplotlib-examples/blob/master/colorline.ipynb
>
> In*Example 1. Sine wave colored by time (uses the defaults for
> colorline)*, how can one add a colorbar?
>
> --V
>
> ------------------------------------------------------------------------------
> HPCC Systems Open Source Big Data Platform from LexisNexis Risk
> Solutions
> Find What Matters Most in Your Big Data with HPCC Systems
> Open Source. Fast. Scalable. Simple. Ideal for Dirty Data.
> Leverages Graph Analysis for Fast Processing & Easy Data Exploration
> http://p.sf.net/sfu/hpccsystems
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> <mailto:Mat...@li...>
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
Thanks for your response to my request, Ray. I had looked at this 
approach earlier; but, what I really need is something like is produced 
by the following code for the cax object:
"""Produce custom labelling for a colorbar.
 Original Script: Scott Sinclair
 Modification: V. Stokes
"""
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.colors as col
from matplotlib import cm
from numpy.random import randn
def register_cmap():
 """
 Purpose: define colormap using the from_List() method as a
 segmented list and register it.
 """
 cmap_Name = 'reyegr' # my colormap name
 startcolor = '#00AF33' # truegreen
 midcolor = '#FFE600' # yolk (a medium dark yellow)
 endcolor = '#FF0033' # bright red
 cmap2 = col.LinearSegmentedColormap.from_list(cmap_Name,
[startcolor,midcolor,endcolor])
 cm.register_cmap(cmap=cmap2)
 return cm.get_cmap(cmap_Name) # my new cmap for 'reylgr'
#-----------------------------------------------------------------------------
my_cmap = register_cmap()
## Vertical colorbar-1
fig, ax = plt.subplots()
data = np.clip(randn(250, 250), -1, 1)
cax = ax.imshow(data, interpolation='nearest', cmap=my_cmap)
ax.set_title('Gaussian noise with vertical colorbar')
# Add colorbar, make sure to specify tick locations to match desired 
ticklabels
cbar = fig.colorbar(cax, ticks=[-1, 0, 1])
cbar.ax.set_yticklabels(['<-1', '0', '> 1'])# vertically oriented colorbar
## Vertical colorbar-2
fig, ax = plt.subplots()
data = np.clip(randn(50, 50), -1, 1)
#cax = ax.imshow(data, interpolation='nearest', cmap=cm.coolwarm)
cax = ax.imshow(data, interpolation='nearest', cmap=my_cmap)
ax.set_title('Gaussian noise with vertical colorbar')
# Add colorbar, make sure to specify tick locations to match desired 
ticklabels
cbar = fig.colorbar(cax, ticks=[-1, 0, 1])
# Vertically oriented (by default) colorbar
cbar.ax.set_yticklabels(['Low', 'Medium', 'High'])
## Horizontal colorbar
fig, ax = plt.subplots()
#
cax = ax.imshow(data, interpolation='nearest', cmap=my_cmap)
ax.set_title('Gaussian noise with horizontal colorbar')
cbar = fig.colorbar(cax, ticks=[-1, 0, 1], orientation='horizontal')
cbar.ax.set_xticklabels(['Low', 'Medium', 'High'])# horizontal colorbar
plt.show()
But, for a colorline object, which was referenced in the link given in 
my earlier email.
--V

On 2014年06月15日, 12:17 PM, Virgil Stokes wrote:
> There are some rather nice and useful matplotlib examples for colormaps
> that are shown at:
>
> http://nbviewer.ipython.org/github/dpsanders/matplotlib-examples/blob/master/colorline.ipynb
>
> In*Example 1. Sine wave colored by time (uses the defaults for
> colorline)*, how can one add a colorbar?
lc = colorline(x, y)
cbar = fig.colorbar(lc)
Eric
>
> --V
>
>
> ------------------------------------------------------------------------------
> HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions
> Find What Matters Most in Your Big Data with HPCC Systems
> Open Source. Fast. Scalable. Simple. Ideal for Dirty Data.
> Leverages Graph Analysis for Fast Processing & Easy Data Exploration
> http://p.sf.net/sfu/hpccsystems
>
>
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Hi Virgil,
I did something very much like this recently by simply adding an axes to my
figure and using it to show a linspace of the data range off which the line
color was based. See
http://matplotlib.org/examples/color/colormaps_reference.html.
Best,
Ray
On Sun, Jun 15, 2014 at 6:17 PM, Virgil Stokes <vs...@it...> wrote:
> There are some rather nice and useful matplotlib examples for colormaps
> that are shown at:
>
>
> http://nbviewer.ipython.org/github/dpsanders/matplotlib-examples/blob/master/colorline.ipynb
>
> In* Example 1. Sine wave colored by time (uses the defaults for
> colorline)*, how can one add a colorbar?
>
> --V
>
>
> ------------------------------------------------------------------------------
> HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions
> Find What Matters Most in Your Big Data with HPCC Systems
> Open Source. Fast. Scalable. Simple. Ideal for Dirty Data.
> Leverages Graph Analysis for Fast Processing & Easy Data Exploration
> http://p.sf.net/sfu/hpccsystems
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>

There are some rather nice and useful matplotlib examples for colormaps 
that are shown at:
http://nbviewer.ipython.org/github/dpsanders/matplotlib-examples/blob/master/colorline.ipynb
In*Example 1. Sine wave colored by time (uses the defaults for 
colorline)*, how can one add a colorbar?
--V