Is it possible to have a zero value in the pie-chart data in MATLAB 7.6 (R2008a)?

When plotting a pie-chart with any one of the data values as zero and a user-defined colormap,unexpected colors are skipped. I also get a warning message

 "Warning: Ignoring non-positive data in pie chart."

With first value as 0, it skips green(second value on colormap)

Dat = [0 10 20 40]

t1col = [1 0 0];   %red        

t2col = [0 1 0];   %green

t3col = [0 0 1];   %blue

t4col = [1 0 1];   %magenta

tilecolor = [t1col; t2col; t3col; t4col]; 

pie(Dat)

colormap(tilecolor)

With second value as 0, it skips green again

dat = [5 0 20 40]

t1col = [1 0 0];   %red        

t2col = [0 1 0];   %green

t3col = [0 0 1];   %blue

t4col = [1 0 1];   %magenta

tilecolor = [t1col; t2col; t3col; t4col]; 

pie(dat)

colormap(tilecolor)

Answer 1

[MathWorks Support Team]

The ability to handle zero values in pie-chart is not available in MATLAB 7.6 (R2008a).

To work around this issue, use the attached function pie_modified(dat,tilecolor)

where variable 'Dat' is the data values for the pie chart and variable 'tilecolor' is the colormap for it. For example:

Dat = [0 10 20 40]

t1col = [1 0 0];   %red        

t2col = [0 1 0];   %green

t3col = [0 0 1];   %blue

t4col = [1 0 1];   %magenta

tilecolor = [t1col; t2col; t3col; t4col]; 

pie_modified(Dat,tilecolor)

Answer 2

[Tasnuba Siddiqui]

rr = [9 1 0 3 4]; % Data

labels = {'M', 'T', 'W', 'TH', 'F'}

z =(rr == 0); % Logical Array

tt = z*realmin; % Minimum No multiplied

rr = rr + tt;   % Added

phr = pie (rr);

colormap([0 1 0;      %// green
          .5 .5 .5;  %// grey
          0 0 1;      %// blue
          1 0 1;      %// magenta
          1 0 0])  %//  red

hText = findobj(phr,'Type','text'); % text object handles

percentValues = get(hText,'String'); % percent values

combinedtxt = strcat(labels,percentValues); % strings and percent values

hText(1).String = combinedtxt(1);

hText(2).String = combinedtxt(2);

hText(3).String = combinedtxt(3);

hText(4).String = combinedtxt(4);

hText(5).String = combinedtxt(5);

It worked for me.

Answer 3

[KAE]

If you are doing this to plot a pie which is missing a slice, see here ('Partial Pie').