How to overcome the data length issue in the following code?

Question

muhammad choudhry ，2022-3-10

0
链接

Direct link to this question

https://ww2.mathworks.cn/matlabcentral/answers/1668779-how-to-overcome-the-data-length-issue-in-the-following-code

评论： Image Analyst ，2022-3-10

Hi,

I have 2 excel files named TimeStamps_Uy.xlsx and Head_Timestamps.xlsx. In file one: TimeStamps_Uy.xlsx column 1 have a Timestamps and column 2 have the velocity data. In file two: column 1 have a Timestamps and column 2 have the Head data. I want to use TimeStamps_Uy.xlsx file and all of its Timestamps to find the similar or the nearest Timestamps in the Head_Timestamps.xlsx hence on matching plot the corresponding data (head/Uy) hence save the timestamp, head, and Uy into new xlsx or csv file. I have tried the intern1 function so far in which I am having problem because in file Head_Timestamps.xlsx there are more data then the TimeStamps_Uy.xlsx. I am pasting the code and error below?

Code:

close all; clear all; clc;

Uy_dir = 'F:\3-PIV_Experimental_Data\Outlet_110\Data_LaserSheet_D\Data_PIV\5-AverageFilter_VelocitiesExtration\Point_Velocities\Uy\TimeStamps_Uy.xlsx';

a = readmatrix(Uy_dir);

time_stamp_u=a(:,1);

u=a(:,2);

Head_dir = 'F:\3-PIV_Experimental_Data\Outlet_110\Data_LaserSheet_D\Data_Head\Data_Raw\Head_Timestamps.xlsx';

a1 = readmatrix(Head_dir);

time_stamp_h=a1(:,1);

h=a1(:,2);

h_u = interp1(h,u,time_stamp_u)

Error:

Error using interp1>reshapeAndSortXandV (line 445)

X and V must be of the same length.

Error in interp1 (line 128)

[X,V,orig_size_v] = reshapeAndSortXandV(X,V);

0 个评论
显示隐藏 -1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

Image Analyst 2022-3-10

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1668779-how-to-overcome-the-data-length-issue-in-the-following-code#answer_914769

"I have 2 excel files named TimeStamps_Uy.xlsx and Head_Timestamps.xlsx." Yes, you have them, but we don't because you forgot to attach them.

h and u are not the same lengths. What are the sizes of those arrays

size(h)
size(u)
size(time_stamp_u)

2 个评论
显示隐藏 1更早的评论

Image Analyst 2022-3-10

See -- h and u have different lengths. You need to pass in the full x first, then the full y, then the x values that you want the interpolated values for the third argument. So the full x and y must be the full signal that you have and must be the same length since you have a y for every x.

请先登录，再进行评论。