Updating a colorbar

Community matplotlib-users
1

Hi,

  Suppose you do this:

  axes = self.figure().get_axes()

  contour = axes.contourf(x,y,z)

  colorbar = self.figure().colorbar(contour)

  Suppose that the contour data changes, can you update the colorbar

with the new data?

  Currently I remove the colorbar and insert a new one - but I have

a feeling that something smarter could be done.

  Best regards,

  Mads
··· 
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mads.ipsen@…287…

2

Mads,

···

On Thu, Jun 28, 2012 at 3:12 AM, Mads Ipsen <madsipsen@…287…> wrote:

Hi,

  Suppose you do this:



  axes = self.figure().get_axes()

  contour = axes.contourf(x,y,z)

  colorbar = self.figure().colorbar(contour)



  Suppose that the contour data changes, can you update the colorbar

with the new data?

  Currently I remove the colorbar and insert a new one - but I have

a feeling that something smarter could be done.

  Best regards,



  Mads

The only way I could think of to do what you want a bit more intelligently is to reuse the existing QuadContourMesh that comes from the initial call to contourf. Updates to that “ScalarMappable” object should then trigger updates to the existing colorbar. Not entirely sure which code would be cleaner, though, because reusing a QuadContourMesh isn’t easy.

Cheers!
Ben Root

3

Hi,

Suppose you do this:

axes = self.figure().get_axes()
contour = axes.contourf(x,y,z)
colorbar = self.figure().colorbar(contour)

Suppose that the contour data changes, can you update the colorbar with
the new data?

Currently I remove the colorbar and insert a new one - but I have a
feeling that something smarter could be done.

When you say "the contour data changes", I assume you mean you are contouring a new set of data, with new contour levels, and not just changing the cmap. In this case there is no point in trying to save something from the old colorbar, so remaking it is the right thing to do. Simple, effective, foolproof. (If only the cmap is changed, then the existing colorbar should be getting updated automatically.)

Eric

···

On 06/27/2012 09:12 PM, Mads Ipsen wrote:

Best regards,

Mads