How to remove contour line in filled contour plot?

Hi all,

I am plotting a data using contourf but the there is a contour line between the start and end value color even after using the

contourf(x,y,z,'LineStyle','none','linecolor','none')
%or
contourf(x,y,z,'LineStyle','none')
%or
contourf(x,y,z,'linecolor','none')

For example in the attached figure there is a line between dark blue and dark red.

Also, I have tried different colormap but the result is same.

Answer 1

[DGM]

Hmm. I didn't think about that. I don't know that it can be done with contourf().

% make a simple linear ramp that cycles
[xx yy] = meshgrid(1:100);
zz = xx;
zz = circshift(zz,[0 -30]);

% this is what happens with contourf()
[~,h] = contourf(xx,yy,zz,9,'linecolor','none');
colormap(jet)
colorbar

% let's try to replicate it with pcolor()
clf; pcolor(xx,yy,zz);
colormap(jet(10)) % set length to number of levels+1
colorbar
shading flat

That's about right. I think it makes the colorbar easier to read anyway.

[UTKARSH VERMA]

I did it with pcolor too and result is same.

Please check the attached figure and data

and the code I used is :

clf
pcolor(d{1},d{2},d{3}');%,'LineStyle','none')
ylim([0 38]);
xlim([65 98]);
yticks([0:5:38]);
xticks([65:05:98]);
colormap(hsv)
colorbar
shading interp

[DGM]

Don't use shading interp. When you use shading interp, it will interpolate between the endpoints. It's helpful to understand that what you're looking at with pcolor() is essentially a top-down view of a surf() plot. Note how it interpolates between the maximal values and the minimal values at those boundaries. That transition is steep, but it's not perfectly vertical -- and so all those colors are visible in a narrow line.

Using shading flat doesn't do that:

and so those transition slopes don't show up:

[UTKARSH VERMA]

Thanks DGM!!

It worked perfectly.

Answer 2

[KSSV]

Try:

pcolor(x,y,z) ;
colorbar ;
shading interp ; 

[UTKARSH VERMA]

Hi KSSV,

I tried your suggestion but same problem.

So, I have attached my data and here is the code I am using:

contourf(d{1},d{2},d{3}','LineStyle','none')
ylim([0 38]);
xlim([65 98]);
yticks([0:5:38]);
xticks([65:05:98]);
colormap(hsv) %or use jet
colorbar