Finding data points of two different matrices based off of time

I have one matrix with data in the first column and time stamps in the second column (datamatrix.mat). The next matrix contains spiketimes (spiketimematrix.mat). I want to get the data point in the first column of first matrix that is the closest time point corresponding to the spike times in spiketimematrix.mat. For example, the first spiketime is 166.1670, which corresponds to the closet time point of 166.1696 and corresponds with the data point 2.5281. I have tried using the following code:

 for k=1:length(spiketimesmatrix)
 dataout(k)=datamatrix(find(spiketimesmatrix>=datamatrix(:,2),1);
 end

I keep getting the first data point as the entire dataoutput.

Not sure if this is clear enough.

[Krispy Scripts]

I am getting the same value repeatedly the size of the spikematrix and I am not sure why.

Answer 1

[Chris Dischner]

Why not use a difference?

First matrix, a, second matrix b:

for i = 1:length(a)
  [m,idx] = min(abs(a(i,2))-b(:,1));
  minVal(i) = a(idx,1);
end

Answer 2

[Walter Roberson]

 dataout(k)=datamatrix(find(spiketimesmatrix(k)>=datamatrix(:,2),1);

[Krispy Scripts]

My data output is the first value repeated over and over again? I am guessing this is something I am doing incorrectly?

[Krispy Scripts]

Actually its not getting the first value, I am not sure what value it is getting, but it is getting it repeatedly over and over again