index array to access the value in matrix

2019 11 14
1 个回答
回答已采纳
更新时间：2019 11 15
4 次查看（30 天）

0 个投票

Hi all, I have 3 matrixes as matrix IM (200x200); X(400x400); Y(400x400). As matrix x and y is indexing the matrix IM. How can I use x and y matrix to access the value of matrix IM withouf for loop.

2 个评论
显示 无 隐藏 无

Shubham Gupta
Shubham Gupta 2019-11-14
Can you please share mat file or put a small example to show what is stored in X,Y & IM?
Small example can be like X&Y of size 4x4 & IM being 2x2, then you can show desired output for this example.
AniCnx
AniCnx 2019-11-14
IM=4.08809852121212 4.29250344727273 4.39470591030303 4.44580714181818 4.44580714181818 4.54800960484849 4.65021206787879 4.75241453090909 4.80351576242424 4.95681945696970
4.39470591030303 4.44580714181818 4.49690837333333 4.54800960484849 4.59911083636364 4.65021206787879 4.75241453090909 4.80351576242424 4.85461699393939 4.95681945696970
4.34360467878788 4.44580714181818 4.49690837333333 4.59911083636364 4.59911083636364 4.65021206787879 4.75241453090909 4.80351576242424 4.80351576242424 4.90571822545455
4.34360467878788 4.39470591030303 4.49690837333333 4.59911083636364 4.59911083636364 4.70131329939394 4.75241453090909 4.75241453090909 4.75241453090909 4.85461699393939
4.29250344727273 4.39470591030303 4.44580714181818 4.54800960484849 4.59911083636364 4.70131329939394 4.70131329939394 4.75241453090909 4.80351576242424 4.80351576242424
4.29250344727273 4.34360467878788 4.44580714181818 4.54800960484849 4.59911083636364 4.70131329939394 4.75241453090909 4.75241453090909 4.80351576242424 4.80351576242424
4.29250344727273 4.34360467878788 4.39470591030303 4.49690837333333 4.59911083636364 4.70131329939394 4.75241453090909 4.80351576242424 4.80351576242424 4.80351576242424
4.29250344727273 4.34360467878788 4.39470591030303 4.49690837333333 4.59911083636364 4.75241453090909 4.75241453090909 4.75241453090909 4.80351576242424 4.80351576242424
4.34360467878788 4.34360467878788 4.39470591030303 4.49690837333333 4.59911083636364 4.70131329939394 4.80351576242424 4.80351576242424 4.80351576242424 4.85461699393939
4.44580714181818 4.44580714181818 4.39470591030303 4.49690837333333 4.59911083636364 4.70131329939394 4.75241453090909 4.75241453090909 4.80351576242424 4.80351576242424
x=1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8
9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9
9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9
10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
y=1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Shubham Gupta
Shubham Gupta 2019-11-14

0 个投票

Step1 - Convert the subscript to indeces using x & y(Hint: sub2ind)
Step2 - Calculate values of IM for calculated indeces
Step3 - Reshape it to match the dimesion with x or y (Hint: reshape)
Something like this:
output = reshape(IM(sub2ind(size(IM),x(:),y(:))),size(x,1),size(x,2));
Let me know if you have doubt

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Resizing and Reshaping Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by