title: Pandas algos package: where to find documentation OR more info on "is_monotonic_float64"
body: <p>someone pointed me to a function in pandas.algos a couple of days ago (see <a href="https://stackoverflow.com/a/17705498/2565842">https://stackoverflow.com/a/17705498/2565842</a>) and I can't find any documentation on this. When I type "algos" or "is_monotonic_float64" (the function in question) in the pandas search box on <a href="http://pandas.pydata.org/pandas-docs/dev/" rel="nofollow noreferrer">http://pandas.pydata.org/pandas-docs/dev/</a>, I don't get any results. Similarly, when I ask Google I don't get anything useful either.</p>
  
  <p>The reason why I am looking for the docs is that I am having trouble with the types the function accepts. I have written two functions like this:</p>
  
  <pre><code>def is_monotonic(time_series, cols):
      return time_series.loc[:,cols].apply(lambda x: 
             pandas.algos.is_monotonic_float64(x)[0] if is_type(x, float) else "non_numeric data", 
             axis=1)
  
  def is_type(series, t):
      return series.apply(lambda x: type(x) == t).all()
  </code></pre>
  
  <p>I run this on the following dataframe</p>
  
  <pre><code>           0          1          2          3          4
  A          t          t          t          t          t
  B  0.2583974  0.3311106   0.933452        NaN  0.1908287
  C  0.4400121  0.9548238  0.2953693  0.7027355  0.6149148
  D  0.4049013  0.5930965  0.7073495  0.3801416  0.4931772
  </code></pre>
  
  <p>but then get as error</p>
  
  <pre><code>ValueError: ("Buffer dtype mismatch, expected 'float64_t' but got Python object"
  </code></pre>
  
  <p>When I check the types in the dataframe, the first row is strings, the others of type 'float'. Do I need to do some sort of type conversion to numpy.float64 here? </p>