diff -r c55016431358 -r 0a7b44b10206 symport/e32/euser/maths/um_utl.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/symport/e32/euser/maths/um_utl.cpp Thu Jun 25 15:59:54 2009 +0100 @@ -0,0 +1,110 @@ +// Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies). +// All rights reserved. +// This component and the accompanying materials are made available +// under the terms of the License "Symbian Foundation License v1.0" +// which accompanies this distribution, and is available +// at the URL "http://www.symbianfoundation.org/legal/sfl-v10.html". +// +// Initial Contributors: +// Nokia Corporation - initial contribution. +// +// Contributors: +// +// Description: +// e32\euser\maths\um_utl.cpp +// +// + +#include "um_std.h" + +#if defined(__USE_VFP_MATH) && !defined(__CPU_HAS_VFP) +#error __USE_VFP_MATH was defined but not __CPU_HAS_VFP - impossible combination, check variant.mmh +#endif + +GLDEF_C void Panic(TMathPanic aPanic) +// +// Panic the process with USER-Math as the category. +// + { + + User::Panic(_L("USER-Math"),aPanic); + } + + + +#ifdef __USE_VFP_MATH +extern "C" void __set_errno(TInt errno) + { + // Do nothing, we don't have an errno to set as we use + // return values instead - return values are recosntructed + // from the results/inputs, not from this + } + +extern "C" IMPORT_C TReal __ARM_scalbn(TReal,TInt); +extern "C" TReal scalbn(TReal x,TInt n) + { + return __ARM_scalbn(x,n); + } +#endif + + + +#ifndef __REALS_MACHINE_CODED__ +EXPORT_C TReal Math::Poly(TReal aX,const SPoly *aPoly) +/** +Evaluates the polynomial: +{a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}. + + +@param aX The value of the x-variable +@param aPoly A pointer to the structure containing the set of coefficients + in the order: a[0], a[1], ..., a[n-1], a[n]. + +@return The result of the evaluation. +*/ +// +// Evaluate a power series in x for a P_POLY coefficient table. +// Changed to use TRealX throughout the calculation +// + { + + const TReal *pR=(&aPoly->c[aPoly->num-1]); + TRealX r(*pR); + TRealX x(aX); + while (pR>&aPoly->c[0]) + { + r*=x; + r+=*--pR; + } + return(TReal(r)); + } + + + + +EXPORT_C void Math::PolyX(TRealX& aY, const TRealX& aX, TInt aDegree, const TRealX *aCoeff) +/** +Evaluates the polynomial: +{a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}. + +@param aY A reference containing the result. +@param aX The value of the x-variable. +@param aDegree The degree of the polynomial (the highest power of x + which is present). +@param aCoeff A pointer to a contiguous set of TRealX values containing + the coefficients. + They must be in the order: a[0], a[1], ..., a[n-1], a[n]. +*/ + { + // Evaluate a polynomial with TRealX argument and TRealX coefficients. + // Return a TRealX result. + + const TRealX *pC=aCoeff+aDegree; + aY=*pC; + while(aDegree--) + { + aY*=aX; + aY+=*--pC; + } + } +#endif