Interpulating multipule sets of data without loops

Hello,

I am trying to do 1D interpulation on multipule sets of data without using loops.

If I must use a loop, the code would look as follows:

X ; % set of grid points, where each column is a different set
V ; % set of data points, where each column is a different set
xq ; % new grid points I would like to interpulate V at.
% Note that size(X) is the same as size(V) and they are both 2D
% All these values are defined priorly in the code.

Vq = zeros(length(xq),size(V,2)) ;
for i=1:size(X,2)
    Vq(:,i) = interp1(X(:,i),V(:,i),xq);
end

Is there a way I can run a simular algorithem without running this loop?

Thank you in advance.

[Fifteen12]

Can you explain what (size(X,1),1) means? Are you saying that xq has the same number of rows as X?

[Fifteen12]

Maybe try splitapplly? Sorry I don't have time to run the code on this.

Answer 1

[Tejas]

Hello Ariel,

To perform 1-D interpolation on multiple sets of data without using a loop, consider these steps:

• Create a function handle that utilizes the 'interp1' function for 1-D interpolation on a given column of 'X' and 'V'.

    interpFcn = @(col) interp1(X(:, col), V(:, col), xq); 

• Use 'arrayfun' to apply this function to each column of 'X' and 'V', storing the results in 'Vq'.

    Vq = arrayfun(interpFcn, 1:size(X, 2), 'UniformOutput', false);
    Vq = cell2mat(Vq);

For more information on the 'arrayfun' function, refer to this documentation: https://www.mathworks.com/help/releases/R2021a/matlab/ref/arrayfun.html