handle h is empty while calling my function more than once

hi,

In my plotting function shown below, handle h is empty (even though i can see in my workspace its value) when the function is called more than once. This happens only if i call this function more than once. For the first time it plots my curve just fine.

Is there something wrong with my code? Can I use something other that findobj? Please advise

function logPlot(i, idx, color, hObject, eventdata, handles)
global wlog
X = wlog.sel_curves(:,idx);
Y = wlog.sel_curves(:,1);
h = findobj(gcf,'tag',strcat('Log',num2str(i)));
plot( X, Y, 'Parent', h, 'color', color);
if i == 1    
   set(h, 'YDir', 'reverse','XYTickLabel', sprintf('%5.2f', wlog.sel_curves(:,1)));
   Ylabel(h, strcat(wlog.sel_curve_info(1,1), ' (',wlog.sel_curve_info(1,2),')'));
else
   set(h, 'YDir', 'reverse', 'XTickLabel', [], 'YTickLabel', []);
end

Answer 1

[Walter Roberson]

We do not know if "hold" is on for the axes or not. If it is not then the before before adding any high-level graphic object is to clear out the existing graphics objects in the axes, which could potentially remove the object with the desired tag (if it is in the same axes.)

[salamay]

hold is not on

I want to plot a new curve and delete the previous plot