title: Interpolating data fails: grid vectors do not define a grid of points that match the given values
body: <p>I have some time/frequency data and I try to interpolate it using the <code>interp2</code> function of Matlab. The data <code>[F,T,data]</code> is obtained from a different Matlab routine of Matlab, spectrogram in case you are interested. </p>
  
  <pre><code>[~,F,T,data] = spectrogram(...)
  data = 10*log10(data);
  </code></pre>
  
  <p>I can plot the data using <code>surf</code>. The data is fine, I believe. However interpolating the data seems to be a problem. Even using <code>interp2(F,T,data,F,T)</code> (so actually no interpolating) gives the error below.</p>
  
  <p>What is going wrong here?</p>
  
  <p>I have the data which I use here: <a href="https://www.dropbox.com/s/zr5zpfhp6qyarzw/test.mat" rel="nofollow noreferrer">https://www.dropbox.com/s/zr5zpfhp6qyarzw/test.mat</a></p>
  
  <pre><code>interp2(F,T,data,f,t)
  Error using griddedInterpolant
  The grid vectors do not define a grid of points that match the given values.
  Error in interp2&gt;makegriddedinterp (line 228)
      F = griddedInterpolant(varargin{:});
  Error in interp2 (line 128)
          F = makegriddedinterp({X, Y}, V, method,extrap);
  &gt;&gt; size(F),size(T),size(data),size(f),size(t)
  ans =
     129     1
  ans =
       1    52
  ans =
     129    52
  ans =
     200     1
  ans =
       1   121
  </code></pre>