Interpolation is wrong?

Hi everyone!

I have a variable, 'wc_average' that I'd like to interpolate so it's the same size as another variable 'dep_cal2012'. Wc_average is about 78x1 and 'dep_cal2012' is about 977x1. The spacing between every point in wc_average is about every 10 minutes while the spacing between every measurement in dep_cal2012 is every nanosecond (there are about 7 measurements taken within the same second). I've tried interpolating wc_average with this code:

x=dep_cal2012; y=wc_average;

ix = linspace(1, numel(x), numel(y));

WC_interp = interp1(ix, y, 1:numel(x),'nearest'); WC_cap=WC_interp';

However, I've tried comparing the timeseries between the two and the interpolated one isn't right.

The code to run the figure:

figure(8787)

subplot(2,1,1)

plot(wcdate_av,wc_average,'-k')

xlabel('date')

title('OG')

subplot(2,1,2)

plot(cr_2012.datetime,WC_cap,'-k')

xlabel('date')

title('Interpolated')

What could be the reasoning behind the wrong interpolation? I've tried every method of interpolation and they all yield the same results.

Answer 1

[KSSV]

x=dep_cal2012; % 977x1 
y=wc_average; % 78x1  
ix = linspace(1, numel(y), numel(x));
WC_interp = interp1(1:numel(y), y,ix,'nearest'); 
WC_cap=WC_interp';

Answer 2

[Sulaymon Eshkabilov]

Here is the corrected code:

x=dep_cal2012; y=wc_average;
ix = linspace(1, max(x), numel(y));
WC_interp = interp1(ix, y, x,'nearest'); WC_cap=WC_interp';