# How to export ParaView colormap into a format that could be read by matplotlib

**URL:** https://discourse.paraview.org/t/how-to-export-paraview-colormap-into-a-format-that-could-be-read-by-matplotlib/2436
**Category:** Tips and Tricks
**Created:** [August 15, 2019, 3:58am UTC](https://discourse.paraview.org/t/how-to-export-paraview-colormap-into-a-format-that-could-be-read-by-matplotlib/2436 "2019-08-15T03:58:21Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![wascott](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/w/8e8cbc/32.png) [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [August 15, 2019, 3:58am UTC](https://discourse.paraview.org/t/how-to-export-paraview-colormap-into-a-format-that-could-be-read-by-matplotlib/2436/1 "2019-08-15T03:58:21Z")

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A beautiful little python function that Cory Quammen created:

Sure, here is a little function that can export the color map in a table:

```auto
def ExportPreset(lutName):
  from paraview import servermanager
  presets = paraview.servermanager.vtkSMTransferFunctionPresets()

  lut = GetColorTransferFunction('dummy')
  lut.ApplyPreset(lutName)

  import vtk
  helper = vtk.vtkUnsignedCharArray()

  dctf = lut.GetClientSideObject()
  dataRange = dctf.GetRange()

  for i in range(0, 256):
    x = (i/255.0) * (dataRange[1]-dataRange[0]) + dataRange[0]
    helper.SetVoidArray(dctf.MapValue(x), 3, 1)
    r = helper.GetValue(0)
    g = helper.GetValue(1)
    b = helper.GetValue(2)
    print("%d %d %d" % (r, g, b))

```

`lutName` is a string with the name of the colormap you’d like to export.

Evaluate and call this function in the **Python Shell** (View -\> Python Shell). You can adapt the script to produce the type of array needed for the `matplotlib` function.

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<div class="post-metadata">

### Author: ![gordon-n-stevenson](https://discourse.paraview.org/user_avatar/discourse.paraview.org/gordon-n-stevenson/32/2287_2.png) [@gordon-n-stevenson](https://discourse.paraview.org/u/gordon-n-stevenson)
#### Post date: [October 24, 2019, 5:17am UTC](https://discourse.paraview.org/t/how-to-export-paraview-colormap-into-a-format-that-could-be-read-by-matplotlib/2436/2 "2019-10-24T05:17:20Z")

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If you want to go the other way around and have a color map in matplotlib or python you want to import into paraview…

```
cmap = lut
#where lut is a colormap of X length by Y as [r,g,b,a]
scheme = 'test'

with open('test.xml', 'w') as fid:
    fid.write('<ColorMaps>\n')
    fid.write('<ColorMap name="{}" space="HSV">\n'.format(scheme))
    N = cmap.shape[0]
    for i in range(N):
        x = [(i-1)/(N-1)] + cmap[i,:].tolist()
        fid.write('<Point x="{:2f}" o="{:2f}" r="{:2f}" g="{:2f}" b="{:2f}" />\n'.format(x[0],x[4],x[1],x[2],x[3]))

    fid.write('</ColorMap>\n')
    fid.write('</ColorMaps>')
```