title: Pairing variables from 2 arrays for use in an equation
body: <p>I am trying to pull 2 separate variable from 2 arrays and have python solve a set of equations using both variables.  I need to use the variables in pairs only, the arrays are already in the correct order so I feel like I just need to enumerate the variables so python only uses each variable once instead of what it is currently doing which is computing every possible combination of the variables.</p>
  <p><code>pa</code> is Phase Angle in radians, such as: 1.20729, 1.20616.</p>
  <p><code>distance</code> is in meters, such as: 34753800.126, 21632361.184.</p>
  <p><code>A</code> = Area and is set to 1</p>
  <p><code>Ref</code> is Reflectivity and is set to 0.175</p>
  <p>The result should be the apparent magnitude of each pair of variables, such as:</p>
  <ul>
  <li>13.6148934 (uses 1.20729 and 34753800.126)</li>
  <li>12.584035  ( uses 1.20616 and 21632361.184)</li>
  </ul>
  <p>I don't want a result that uses 1.20729 and 21632361.184</p>
  <pre><code>with open('ApparentMagnitude.txt', 'w') as output:
      for pa in PA_Rads_Array:
          for distance in Meters_Array:
              P = (1/pi) * (np.sin(pa) + ((pi - pa) * np.cos(pa)))
              RAP = Ref * A * P
              RAPd = RAP/(distance**2)
              M = -26.7 - (2.5 * np.log10(RAPd))
              output.write(str(M) + &quot;\n&quot;)
  </code></pre>