Faster interpolation of 2-D spatial data at different time steps without looping through the time steps?
12 views (last 30 days)
Show older comments
I have a relatively small number of scattered data point locations (~30) which I want to interpolate onto a uniform spatial grid (e.g. 100 x 100). But the data set is also temporally varying, so I need to interpolate each spatial grid thousands (or tens of thousands) of times. Note, that I do not need to interpolate in time, I only need to interpolate spatially at each time step.
I am currently doing this with a for loop, but I am wondering if there is a way to do it faster in one step. See simple example below. Any help is appreciated!
%Create random data points:
xLoc = rand(30,1);
yLoc = rand(30,1);
%Create random data at each point varying temporally with 10000 points:
nT = 10000;
Data = randn(30,nT);
%uniform grid to interpolate onto:
xInt = 0:0.01:1;
yInt = 0:0.01:1;
[X,Y] = meshgrid(xInt,yInt);
%Create interpolant:
F = scatteredInterpolant(xLoc,yLoc,Data(:,1));
%Now loop over each time stamp. <<<--- This is the part I want to speed up
%This example current takes about 1.25 min on my machine, but I presume could
%be faster if I avoided a loop.
tic
V = nan(length(X(:)),nT);
for i = 1:size(Data,2)
F.Values = Data(:,i);
V(:,i) = F(X(:),Y(:));
end
toc
0 Comments
Accepted Answer
Matt J
on 16 Jan 2023
Using func2mat from this FEX download,
%Create random data points:
xLoc = rand(30,1);
yLoc = rand(30,1);
%Create random data at each point varying temporally with 10000 points:
nT = 10000;
Data = randn(30,nT);
%uniform grid to interpolate onto:
xInt = 0:0.01:1;
yInt = 0:0.01:1;
[X,Y] = meshgrid(xInt,yInt);
%Create interpolant:
F = scatteredInterpolant(xLoc,yLoc,Data(:,1));
tic
A=func2mat(@(D) func(D,F,X,Y), Data(:,1) );
V=A*Data;
toc
function V=func(D,F,X,Y)
F.Values=D;
V=F(X(:),Y(:));
end
More Answers (0)
See Also
Categories
Find more on Interpolation in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!