The magic numbers p and b1-b5 were obtained from approximation (2) in Bryc, W. "A uniform approximation to the right normal tail integral", Applied Mathematics and Computation, Volume 127, Issue 2-3 (April 2002), Pages 365-374.
I have added links to this reference in the post if you'd like to look at it.
Where do the magic numbers (p, b1-b5) come from? Are these empirically found using curve fitting?<p>Also, wouldn't it be better to write things like<p><pre><code> (+ (- (* (exp (* (- r) t)) strike) s) call)))
</code></pre>
in a more schemer-friendly way as<p><pre><code> (+ call (- s) (* strike (exp (- (* r t)))))
</code></pre>
to avoid parenthesis syndrome?<p>(I was probably wrong to expect self-explanatory code, e.g. with docstrings, but IMO the readability could be improved)
Black-Scholes Option Pricing Model in C, from the same author:<p><a href="http://blog.ecounysis.com/black-scholes-option-pricing-model-in-c" rel="nofollow">http://blog.ecounysis.com/black-scholes-option-pricing-model...</a>