How can I interpolate time?

Hello everyone.

I have a vector with times called

tim1_1

, of size 51*1, I also have measurements called

lam1_1

made at those times.

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.

Can someone please help me with this problem?

Answer 1

[Star Strider]

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.

.

[Jaime De La Mota Sanchis]

Thanks, I think I can work with this.

[Star Strider]

As always, my pleasure!

.