Labels on the contour have too many digits

How can I set the precision of the numbers on my contour plot? Now the clabels are like: 1.29567, I would like to have it rounded like: 1.3.

Thanks

Answer 1

[Maryam]

I have done the following and it works perfectly:

[c,h]=contourf(X,Y,H); texth=clabel(c,h,'manual','fontsize', 20); for i=1:size(texth) textstr=get(texth(i),'String'); textnum=STR2DOUBLE(textstr); textstrnew=sprintf('%0.3f', textnum) set(texth(i),'String',textstrnew); end

[Johannes S.]

Thank you so much!! I was searching for something like this for about two days now.

Its a german thing, that you need to use a comma for decimal sep. instead of a dot and this is the best solution for the contour levels.

Answer 2

[Matthew Perkins]

I found this works. And seems much easier.  I have R2015b.

[c,h]=contourf(X,Y,H);
  h.LevelList=round(h.LevelList,3)  %rounds levels to 3rd decimal place
  clabel(c,h)

[Tom Shenton]

Great elegant solution. Worked really well.

[MohammadReza Jabbari (Jabari)]

this is worked. thanks

[Zhao Shuaijie]

works well !

thanks

Answer 3

[Moises Jezzini]

An update since this was the first answer in my search. This works for 2014b or above, previous solution does not work, due to a change in the way clabel works.

[X,Y,Z] = peaks;
figure;
[C, ~] = contour(X, Y, Z, 5, 'ShowText', 'on');
tl = clabel(C, 'FontSize', 10);
itvec = 2:2:length(tl);
NewCoutours = zeros(size(itvec));
for i= itvec
    textstr = get(tl(i), 'String');
    NewCoutours(i) = round(str2double(textstr), 2);
end
contour(X,Y,Z, NewCoutours, 'ShowText','on');

Before

After

Answer 4

[Hugo]

You could use

[C,h]=contour(...);
texth=clabel(C,h);

texth is a vector that contains the handles of all labels. To get the value in label number n you can use

textstr=get(texth(n),'String');

textstr is a string of chars, not a number, so you should do

textnum=str2num(textstr);

to convert to a number. Then you can set the precision by using

textstrnew=num2str(textstr,'%1.1g');

and then set the label to

set(texth(n),'String',teststrnew);

Hope this helps.

[Maryam]

Thank you very much for your help. It does not work. This is what I have:

[c,h]=contourf(Xe,Ye,Z,30); texth=clabel(c,h,'fontsize', 20); for i=1:size(texth) textstr=get(texth(i),'String'); textnum=str2num(textstr); textstrnew=num2str(textstr,1); set(texth(i),'String',textstrnew); end

I appreciate your help. Thanks.

[Hugo]

It doesn't work because you wrote "textstrnew=num2str(textstr,1);" instead of what I wrote. The second input argument should be an appropriate one.

Answer 5

[mauricio misraji]

You can add the option to the contour command:

"LabelFormat","%0.1f"

where 0.1 means just 1 decimal digit. For example:

contour(X,Y,Z,levels,'ShowText','on',"LabelFormat","%0.4f")

shows 4 decimal digits.