Python speed vs csharp
Terry Reedy
tjreedy at udel.edu
Thu Jul 31 20:51:16 EDT 2003
"David M. Cooke" <cookedm+news at physics.mcmaster.ca> wrote in message
news:qnkn0eutndk.fsf at arbutus.physics.mcmaster.ca...
> At some point, Mike <mike at nospam.com> wrote:
> > Here's the chunk of code that I'm spending most of my time
executing:
> >
> > # Rational approximation for erfc(x) (Abramowitz & Stegun, Sec.
7.1.26)
> > # Fifth order approximation. |error| <= 1.5e-7 for all x
> > #
> > def erfc( x ):
> > p = 0.3275911
> > a1 = 0.254829592
> > a2 = -0.284496736
> > a3 = 1.421413741
> > a4 = -1.453152027
> > a5 = 1.061405429
> >
> > t = 1.0 / (1.0 + p*float(x))
> > erfcx = ( (a1 + (a2 + (a3 +
> > (a4 + a5*t)*t)*t)*t)*t ) * math.exp(-(x**2))
> > return erfcx
Does inlining the constants give any speedup? or is local lookup so
fast that it does not matter?
TJR
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