index must be a positive integer or logical

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Andrew 2014-8-23

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评论： Andrew 2014-8-23

I have this simple code I'm trying to run but I keep getting the error 'index must be a positive integer or logical.' Basically I'm attempting to make a 32x32 image of the f(x,y) bounded by x=0, x=2 and y=0, y=2

a=1;
b=1;
% dbstop if error
for x=0:.0645:2;
    for y=0:.0645:2;
        f(x,y)=1+sin(2*pi*(a.*x + b.*y));
    end
end
imshow(f)

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Image Analyst 2014-8-23

I fixed the formatting for you but read this: http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Andrew 2014-8-23

Thanks! I'll be sure to keep that in mind next time

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Answer 1

Image Analyst 2014-8-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/152102-index-must-be-a-positive-integer-or-logical#answer_149643

编辑：Image Analyst 2014-8-23

在 MATLAB Online 中打开

Indexes can't start at zero like it said, but like you tried to do. To fix it, if you want to use a for loop, do this:

a=1;
b=1;
% dbstop if error
x=0:.0645:2;
y=0:.0645:2;
for column = 1 : length(x)
  for row = 1 : length(y)
    f(row, column)=1+sin(2*pi*(a.*x(column) + b.*y(row)));
  end
end
imshow(f, [], 'InitialMagnification', 600);
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);