Why am I getting NaN using interp2?
显示 更早的评论
- I have a 450*90 matrix of values
- I want to sample the matrix at 100 random sample points
However, while my interp2 function runs without errors, my output results vector contains NaN values after the 90th index.
The code below results in me getting NaN for points after the 90th index of vals - why, and how do I correct it?
Shouldn't I be able to sample 1 point from the matrix, or 50, or 100, or 1000 points?
Code:
row_vect = 1:450;
col_vect = 1:90;
[X,Y] = meshgrid(col_vect, row_vect);
V = abs(rand(450,90));
Xq = row_vect(1:100);
Yq = randi(89, 1,100);
vals = interp2(X, Y, V, Xq', Yq');
Thanks
采纳的回答
Torsten
2015-8-26
2 个投票
You try to extrapolate in Y-direction.
Read the description part for interp2 under
and you'll see why you get NaN for Y-values greater 90.
Best wishes
Torsten.
3 个评论
macdommy74
2015-8-26
Torsten
2015-8-26
Use
[X,Y] = meshgrid(row_vect, col_vect);
instead of
[X,Y] = meshgrid(col_vect, row_vect);
Best wishes
Torsten.
macdommy74
2015-8-26
更多回答（1 个）
Walter Roberson
2015-8-26
2 个投票
Your problem is your X not your Y. max(X(:)) is 90 because your first argument to meshgrid() is col_vec which is 1:90
类别
在 帮助中心 和 File Exchange 中查找有关 Logical 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
