title: Is there a python (scipy) function to determine parameters needed to obtain a target power?
body: <p>In R there is a very useful function that helps with determining parameters for a two sided t-test in order to obtain a target statistical power.</p>
  
  <p>The function is called <code>power.prop.test</code>.</p>
  
  <p><a href="http://stat.ethz.ch/R-manual/R-patched/library/stats/html/power.prop.test.html">http://stat.ethz.ch/R-manual/R-patched/library/stats/html/power.prop.test.html</a></p>
  
  <p>You can call it using:</p>
  
  <pre><code>power.prop.test(p1 = .50, p2 = .75, power = .90)
  </code></pre>
  
  <p>And it will tell you n the sample size needed to obtain this power. This is extremely useful in deterring sample sizes for tests.</p>
  
  <p>Is there a similar function in the scipy package?</p>