Column-wise interpolation of an NxM matrix?

D G
2012 7 16
3 个回答
27 次查看（30 天）

0 个投票

Hi!
I'm wondering if it is possible to interpolate column-wise along an NxM matrix.
Previous size were:
x = 1x200
Y = 1x200
xi = 1x200
New values are
x = 1x200
Y = 10x200
xi = 1x200
I have a loop that does it now, but would prefer to vectorize it as long as it is readable.
Thanks!

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Jan
Jan 2012-7-16
How do you "interpolate" along a singelton dimension? Could post your loop method - by editing the question, not as comment or answer?

请先登录，再进行评论。

请先登录，再回答此问题。

回答（3 个）

Sean de Wolski
Sean de Wolski 2012-7-16

0 个投票

Sure:
doc interp1

4 个评论
显示 2更早的评论 隐藏 2更早的评论

D G
D G 2012-7-16
编辑：D G 2012-7-16
No, It doesn't work. It gives an error in the griddedInterpolant function.
The size of the grid point arrays should match the size of the
value arrays.
Error in interp1>LinearShiftBounds (line 255)
F = griddedInterpolant(X,V(:,1));
Error in interp1 (line 216)
[X, V] = LinearShiftBounds(X, V, Xq);
Sean de Wolski
Sean de Wolski 2012-7-16
It works just fine...
y = magic(10);
x = (1:10)';
xi = linspace(1,10,50)';
interp1(x,y,xi)
D G
D G 2012-7-16
Try this:
y = magic(10);
x = (1:20)';
xi = linspace(1,10,50)';
interp1(x,y,xi, 'linear', 'extrap');
Why would this fail?
Teja Muppirala
Teja Muppirala 2012-7-17
That fails because y has 10 values, and your x has 20 values. But as Sean said, INTERP1 works perfectly fine. Just transpose your data first:
Yi = interp1(x',Y',xi','linear','extrap')';

请先登录，再进行评论。

Doug Hull
Doug Hull 2012-7-16

0 个投票

Why do you want to vectorize it?
If it is working, and it is apparently readable, wouldn't your time be better spent on other aspects of the code?

类别

在 帮助中心 和 File Exchange 中查找有关 Interpolation 的更多信息

标签

提问:

D G
D G
2012-7-16

Community Treasure Hunt

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

Start Hunting!

Translated by