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Computer Algebra System in Coffeescript

github.com/davidedc/Algebrite

davidedc/Algebrite

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#----------------------------------------------------------------------------- # # Author : philippe.billet@noos.fr # # erfc(x) # # GW Added erfc() from Numerical Recipes in C # #----------------------------------------------------------------------------- Eval_erfc = -> push(cadr(p1)) Eval() yerfc() yerfc = -> save() yyerfc() restore() yyerfc = -> d = 0.0 p1 = pop() if (isdouble(p1)) d = erfc(p1.d) push_double(d) return if isZeroAtomOrTensor(p1) push(one) return push_symbol(ERFC) push(p1) list(2) return # from Numerical Recipes in C erfc = (x) -> if x == 0 return 1.0 t = 0.0 z = 0.0 ans = 0.0 z = Math.abs(x) t = 1.0 / (1.0 + 0.5 * z) ans=t*Math.exp(-z*z-1.26551223+t*(1.00002368+t*(0.37409196+t*(0.09678418+ t*(-0.18628806+t*(0.27886807+t*(-1.13520398+t*(1.48851587+ t*(-0.82215223+t*0.17087277))))))))) if x >= 0.0 return ans else return 2.0-ans