Error in using "shading interp" with logarithmic colorscale

I want to do a shading interp to my plot. It works fine when I use linear(default) colorscale, but when I set the colorscale to "log", the plot on that ax disappeared.

• do shading interp earlier

ax2 = axes;
 m_proj('miller','long',[lon1 lon2],'lat',[lat1 lat2]); %m_proj is function from m_map package
 m_pcolor(X,Y,delta_p); % from m_map package
 shading interp;
 m_grid('linest','none','tickdir','out','box','fancy','fontsize',10); % from m_map package
 axis equal; % "merge" the plots on ax1 and ax2
 set(ax2,'ColorScale','log');
 % >>Warning: Error creating or updating Surface
 % Error in value of property  <a
 % href="matlab:helpUtils.reference.showPropertyHelp('matlab.graphics.primitive.Surface','CData');")">CData</a>
 % DataSpace or ColorSpace transform method failed

Then the plot on ax2 disappeared

• do shading interp later

ax2 = axes; 
 m_proj('miller','long',[lon1 lon2],'lat',[lat1 lat2]);
 m_pcolor(X,Y,delta_p);
 m_grid('linest','none','tickdir','out','box','fancy','fontsize',10);
 axis equal;
 shading interp;
 %>> Warning: Error creating or updating Patch
 %Error in value of property  <a
 %href="matlab:helpUtils.reference.showPropertyHelp('matlab.graphics.primitive.Patch','FaceVertexCData');")">FaceVertexCData</a>
 % Number of colors must equal number of vertices
 %%%%%% This warning appears 5 times. Despite of this warning, shading interp still works

 set(ax2,'ColorScale','log'); 

Then I received the same warning again, but this time the whole plot on ax2 disappeared, only left with the axes.

Then I tried first setting to log scale then shading interp:

ax2 = axes; 
 m_proj('miller','long',[lon1 lon2],'lat',[lat1 lat2]);
 m_pcolor(X,Y,delta_p);
 m_grid('linest','none','tickdir','out','box','fancy','fontsize',10);
 set(ax2,'ColorScale','log');
s1=findobj(ax2,'Type','surf');
set(s1,'FaceColor','interp')    

But I still got the Dataspace/Color Space transform warning, and the plot still disappeared.

Other answers to this issue suggest replace numbers that are close to 0 with NaN, I tried but it still didn't work.

delta_p(delta_p<1e-04)=NaN;

[G A]

doc shading 

It says: The shading function controls the color shading of surface and patch graphics objects.

[Voss]

Related: maybe m_pcolor creates a surface object.

[Siyi Zhang]

Thank you both. I have updated my question.

[G A]

pcolor(peaks);
set(gca,'ColorScale','log');
colormap(parula(256));
shading flat;

works

pcolor(peaks);
set(gca,'ColorScale','linear');
colormap(parula(256));
shading interp

works

pcolor(peaks);
set(gca,'ColorScale','log');
colormap(parula(256));
shading interp;
% Warning: Error creating or updating Surface
 % Error in value of property  CData
 % DataSpace or ColorSpace transform method failed.
 

does not work

[Siyi Zhang]

so it's a bug?

[G A]

I don't think that is a bug. It is just not possible to do in Matlab now. See similar question about transparency.

https://uk.mathworks.com/matlabcentral/answers/63939-transparent-surface-with-log-axis

[Siyi Zhang]

Thanks!!