(PECL trader >= 0.2.0)
trader_correl — Pearson's Correlation Coefficient (r)
$real0
   , array $real1
   [, integer $timePeriod
  ] )
real0
    Array of real values.
real1
    Array of real values.
timePeriod
    Number of period. Valid range from 2 to 100000.
Returns an array with calculated data or false on failure.