1

次のコードがあります。

for i = 1450:9740:89910
    n = i+495;
    range = ['B',num2str(i),':','H',num2str(n)];
    iter  = xlsread('BrokenDisplacements.xlsx' , range);
    displ = iter;
    displ = [displ; iter];
end

これは、必要な範囲の Excel ファイルから値を取得し、マトリックスとして出力します。ただし、このコードは displ の最終値を使用するだけで、そこから総行列を作成します。これらの出力 (displ) を、途中で値を保存する 1 つの大きな行列に合計したいのですが、どうすればよいでしょうか?

4

2 に答える 2

1

これはどう：

displ=[];

for i = 1450:9740:89910
    n = i+495;
    range = ['B',num2str(i),':','H',num2str(n)];
    iter  = xlsread('BrokenDisplacements.xlsx' , range);
    displ = [displ; iter];
end
于 2013-02-26T23:43:28.453 に答える
1

Since you know the size of the block of data you are reading, you can make your code much more efficient as follows:

firstVals = 1450:9740:89910;
displ = zeros((firstVals(end) - firstVals(1) + 1 + 496), 7);
for ii = firstVals
    n = ii + 495;
    range = sprintf('B%d:H%d', ii, ii+495);
    displ((ii:ii+495)-firstVals(1)+1,:) = xlsread('BrokenDiplacements.xlsx', range);
end

Couple of points:

  1. I prefer not to use i as a variable since it is built in as sqrt(-1) - if you later execute code that assumes that to be true, you're in trouble
  2. I am not assuming that the last value of ii is 89910 - by first assigning the value to a vector, then finding the last value in the vector, I sidestep that question
  3. I assign all space in iter at once - otherwise, as it grows, Matlab keeps having to move the array around which can slow things down a lot
  4. I used sprintf to generate the string representing the range - I think it's more readable but it's a question of style
  5. I assign the return value of xlsread directly to a block in displ that is the right size

I hope this helps.

于 2013-02-27T00:12:49.003 に答える