title: Changing Amplitude & Frequency of numpy.sin(wt) in pylab
body: <p>For part of another project, I just need to make a simple sine wave with some frequency f.</p>
  
  <p>Changing "samples" gives some strange effects on the pylab plot and I just don't know why!</p>
  
  <p>using samples=500   gives a plot with  frequency = 1/50 Hz.</p>
  
  <p>using samples=1000  gives a plot with  frequency = 1/100 Hz.</p>
  
  <p>then with larger samples like 5000 and 10000, the plotted wave changes amplitude along the t axis, in patterns.</p>
  
  <pre><code>import numpy as N
  f = 10.
  w = 2. * N.pi * f
  time_interval = 100
  samples = 5000
  t = N.linspace(0, time_interval, samples)
  y = N.sin(w * t)
  pylab.plot(t, y)
  pylab.show()
  </code></pre>
  
  <p>Any help here would be great! I just want a basic sine wave but can't even seem to do that!</p>