MATLAB: How to erase a line

remove

Hai,

I have drawn a few lines. At the later part of my program I need to delete (remove/erase) those lines, which do not satisfy the required conditions. So, is it possible to remove or erase the lines which have already been drawn, in matlab. Is there any function that supports this. Looking for your reply.

BSD

Best Answer

f=figure(1);hold on;
c1=plot(1:10);
c2=plot(10:-1:1);
delete(c1);

Related Solutions

MATLAB: Clear axes – Except image

You can use findobj() like in this function that I often use:

%=====================================================================
% Erases all lines and text from the current axes.  
% The current axes should be set first using the axes() command
% before this function is called, as it works from the current axes, gca.
function ClearLinesFromAxes(handles)
  try
    % Clear line objects.
    axesHandlesToChildObjects = findobj(gca, 'Type', 'line');
    if ~isempty(axesHandlesToChildObjects)
      delete(axesHandlesToChildObjects);
    end
    % Clear text objects.
    axesHandlesToChildObjects = findobj(gca, 'Type', 'text');
    if ~isempty(axesHandlesToChildObjects)
      delete(axesHandlesToChildObjects);
    end
  catch ME
    message = sprintf('Error in ClearLinesFromAxes():\n%s', ME.message);
    uiwait(warndlg(message));
  end
  return; % from ClearLinesFromAxes

Of course you can also do this:

axes(handlesToAxes);
cla reset;
imshow(yourImage);

This might also be pretty fast, though there's a possibility it may flash to white for a fraction of a second before your image redisplays.

MATLAB: Ho to delete the image from the axes

You need to find the image in the axes with findobj() and then delete it. Like this:

axesHandlesToChildObjects = findobj(h, 'Type', 'image');
if ~isempty(axesHandlesToChildObjects)
  delete(axesHandlesToChildObjects);
end

You can't just call cla() or it will delete everything such as text, arrows, overlays, or other annotation you added. Try this full demo:

function test3
% Display an image.
imshow('moon.tif');
axis on;
% Add some text.
text(100,250, 'Moon', 'FontSize', 30, 'Color', 'r');
promptMessage = sprintf('Do you want to clear the image only?');
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'OK', 'Cancel', 'OK');
if strcmpi(button, 'OK')
  % Get rid of image from current axes, but leave text.
  ClearImagesFromAxes(gca)
end
%=====================================================================
% Erases all images from the axes.
function ClearImagesFromAxes(h)
  axesHandlesToChildObjects = findobj(h, 'Type', 'image');
  if ~isempty(axesHandlesToChildObjects)
    delete(axesHandlesToChildObjects);
  end
  return; % from ClearImagesFromAxes

Best Answer

Related Solutions

MATLAB: Clear axes – Except image

MATLAB: Ho to delete the image from the axes

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