# How can I interpolate time?

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Hello everyone.
I have a vector with times called
tim1_1
, of size 51*1, I also have measurements called
lam1_1
tim1_1
goes between 0 and 1.737857815507103e+03. Instead of 51 measurements I want to have an arbitrary number, let's say 200. I have tried to write
interpLam1_1R = interp1(tim1_1,lam1_1,1:tim1_1(end)/200:tim1_1(end),'spline');
Unfortunately, if I plot the obtained results, they don't look like the original ones at all. As can be seen in the attached figure, the original data (in blue) looks almost sinusoidal,meanwhile, the interpolated data looks almost as a straight line.

Star Strider on 8 Nov 2021
Apparently ‘tim1_1’ is not a datetime array.
tim1_1 = linspace(0, 1.737857815507103e+03, 51);
lam_1 = sin(2*pi*1E-3*tim1_1);
tim1_2 = linspace(min(tim1_1), max(tim1_1), 200);
lam_1_2 = interp1(tim1_1, lam_1, tim1_2);
figure
plot(tim1_1, lam_1, '.b')
hold on
plot(tim1_2, lam_1_2, '.r')
hold off
grid
legend('Original','Interpolated', 'Location','best')
Experiment to get different results.
.
##### 2 CommentsShowHide 1 older comment
Star Strider on 9 Nov 2021
As always, my pleasure!
.

R2021b

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