Is there a more efficient method for this matrix calculation?

H
H
2014 3 29
1 个回答
更新时间：2014 3 29
4 次查看（30 天）

0 个投票

Is this the most efficient way to do a calculation on a subset of terms in a matrix? For instance if I have a 23x23 matrix and wanted to replace columns 2 through 22 in rows 2 through 22 by the average of the four adjacent terms? This method seems to recalculate the entire matrix at every step rather than just the individual term.
for i=2:22
for j=2:22
H1(i,j)=0.25*(HOLD(i,j+1)+HOLD(i,j-1)+HOLD(i+1,j)+HOLD(i-1,j));
end
end

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回答（1 个）

Image Analyst
Image Analyst 2014-3-29

0 个投票

Use conv2():
kernel = 0.25 * [0, 1, 0; 1, 0, 1; 0, 1, 0];
H1 = conv2(HOLD, kernel, 'same');

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H
H
2014-3-29

回答：

Image Analyst
Image Analyst
2014-3-29

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