How to speed up a 2D interpolation in MATLAB?

Question

Jack Smith 2023-1-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1900595-how-to-speed-up-a-2d-interpolation-in-matlab

评论： Jack Smith 2023-1-30

I am reading a table from excel which I am using as the basis for a 2D interpolation, I've included an image of the table with the x, y and output variables shown with the sensitive data omitted for reference.

I have sensor data for position and velocity, with the variable names Raw_Position and Raw_Velocity respetively, that are used to interpolate the Output0 value at a given positon and velocity. The sensor data is in the format of n rows and m columns.

Currently I am achieving this using two interp1 functions inside nested for loops that repeat the calculation for every row and column of the sensor data but this is very slow and my script is taking several minutes to run for a large data set. Is there a way to speed up this process with the interp2 function or something similar?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Paul 2023-1-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1900595-how-to-speed-up-a-2d-interpolation-in-matlab#answer_1156220

在 MATLAB Online 中打开

A single call to interp2 should do the trick

Position0 = 1:4;
Velocity0 = 1:5;
Output0 = Position0.' + Velocity0;
RawPosition =[1 2;3 4;1 2]; RawVelocity = [2 3;4 5;1 2];
Output = interp2(Velocity0,Position0,Output0,RawVelocity,RawPosition)
Output = 3×2
     3     5
     7     9
     2     4
% check
RawPosition + RawVelocity
ans = 3×2
     3     5
     7     9
     2     4

3 个评论
显示 1更早的评论隐藏 1更早的评论

Paul 2023-1-25

Hi Jack,

As I showed, the RawPosition and RawVelocity inputs to interp2 can be arrays. In my example they were both 3 x 2, as was the output.

Also, according to our sketch Position0 corresponds to rows of Output0 and Velocity0 corresponds to the columns of Output0. In interp2, the x-coordinate corresponds to the columns and the y-coordinate the rows, which is why in my example I had Velocity as x and Postion as y.

Jack Smith 2023-1-30