Strange phenomenon with large size matrix
Status: Alpha
Brought to you by:
shaiay
Menu
▾
▴
I am testing octplot to print 30 PNG pictures with 4 subplots using looping. And, I choose small spacing for matrix x and y to create a 101x101 matrix
So, It will be a heavy task for slow computer.
Try the following 2 codes listed below:
"massive_print.m" and "massive_print2.m"
The difference is the first one use the set command to set the 'XTick' and 'XTickLabel' which is not used in the second one.
However, the second one, "massive_print2.m", usually has runtime error while the first one, "massive_print.m", is less likely to have runtime error.
Why does it so strange?
Note: when you use a small matrix size for x, y and z, there will be no error for both cases.
-----------------------------------------------------------------
1. Save the code below into "massive_print.m"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% if use the "set" command %
% No runtime error with text %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Please run this script under a sub-directory
% it will save the picture "1.png" to "30.png"
% For exmaple, create a sub-directory "test-massive"
% mkdir test_massive; cd test_massive;
octplot_enable;
for index=1:30
x=[0:0.05:5];
y=[(index-1):0.05:(index+4)];
z=zeros(101);
for i=1:101
for j=1:101
z(i,j)=x(i)+y(j)+sin(y(j));
end
end
subplot(2,2,1);
colormap('rainbow');
contour(x,y,z,linspace(0,30,50));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
set(gca(),'XTick',[0 1 2 3 4 5]);
set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,2);
colormap('rainbow');
contour(x,y,z,linspace(0,35,80));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
set(gca(),'XTick',[0 1 2 3 4 5]);
set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,3);
colormap('rainbow');
contour(x,y,z,linspace(0,40,90));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
set(gca(),'XTick',[0 1 2 3 4 5]);
set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,4);
colormap('rainbow');
contour(x,y,z,linspace(0,50,100));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
set(gca(),'XTick',[0 1 2 3 4 5]);
set(gca(),'XTickLabel','0|1|2|3|4|5');
prtcmdstr=strcat("print -r100 -dpng ",num2str(index),".png;");
eval(prtcmdstr);
pause(4);
end
----------------------------------------------------------------
2. Save the code below into "massive_print2.m"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% if do not use the "set" command %
% with runtime error with text %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Please run this script under a sub-directory
% it will save the picture "1.png" to "30.png"
% For exmaple, create a sub-directory "test-massive"
% mkdir test_massive; cd test_massive;
octplot_enable;
for index=1:30
x=[0:0.05:5];
y=[(index-1):0.05:(index+4)];
z=zeros(101);
for i=1:101
for j=1:101
z(i,j)=x(i)+y(j)+sin(y(j));
end
end
subplot(2,2,1);
colormap('rainbow');
contour(x,y,z,linspace(0,30,50));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
%set(gca(),'XTick',[0 1 2 3 4 5]);
%set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,2);
colormap('rainbow');
contour(x,y,z,linspace(0,35,80));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
%set(gca(),'XTick',[0 1 2 3 4 5]);
%set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,3);
colormap('rainbow');
contour(x,y,z,linspace(0,40,90));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
%set(gca(),'XTick',[0 1 2 3 4 5]);
%set(gca(),'XTickLabel','0|1|2|3|4|5');
subplot(2,2,4);
colormap('rainbow');
contour(x,y,z,linspace(0,50,100));
axis([0 5 index-1 index+4]);
axis('equal');
title(num2str(index));
text(3.5,index+4.3,strcat("num=",num2str(index,"%6.2f")));
%set(gca(),'XTick',[0 1 2 3 4 5]);
%set(gca(),'XTickLabel','0|1|2|3|4|5');
prtcmdstr=strcat("print -r100 -dpng ",num2str(index),".png;");
eval(prtcmdstr);
pause(4);
end
----------------------------------------------------------------
I ran both the m-files on current svn (which is basically octplot 0.4.0) and octave 2.9.10+ without any runtime error.
Can you give us some more info? octplot version, octave version, OS? This is not a problem with slow cpu or little memory -- my dev laptop is 800Mhz P3 with 256 MB Ram -- you probably can't get much slower than that ...
Shai
p.s. I took the liberty to change the for-loop you use to populate z with the following one-liner (which is of course much faster):
z = x'*ones(1,101) + ones(101,1)*(y + sin(y));
This problem only happens when I try it with the unstable "native MSVC compiled" version of Octave 2.9.9 with Octplot 0.3.9+. But it is strange to me that why there is such a difference with minor change in the script.
Again, No error for both cases when I use Octplot 0.4.0 with Octave 2.1.73 in Cygwin.