1 // Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of the License "Symbian Foundation License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.symbianfoundation.org/legal/sfl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // e32\euser\maths\um_utl.cpp

    15 // 

    16 //

    17 

    18 #include "um_std.h"

    19 

    20 #if defined(__USE_VFP_MATH) && !defined(__CPU_HAS_VFP)

    21 #error	__USE_VFP_MATH was defined but not __CPU_HAS_VFP - impossible combination, check variant.mmh 

    22 #endif

    23 

    24 GLDEF_C void Panic(TMathPanic aPanic)

    25 //

    26 // Panic the process with USER-Math as the category.

    27 //

    28 	{

    29 

    30 	User::Panic(_L("USER-Math"),aPanic);

    31 	}

    32 

    33 

    34 

    35 #ifdef __USE_VFP_MATH

    36 extern "C" void __set_errno(TInt errno)

    37 	{

    38 	// Do nothing, we don't have an errno to set as we use

    39 	// return values instead - return values are recosntructed

    40 	// from the results/inputs, not from this

    41 	}

    42 

    43 extern "C" IMPORT_C TReal __ARM_scalbn(TReal,TInt);

    44 extern "C" TReal scalbn(TReal x,TInt n)

    45 	{

    46 	return __ARM_scalbn(x,n);

    47 	}

    48 #endif

    49 

    50 

    51 

    52 #ifndef __REALS_MACHINE_CODED__

    53 EXPORT_C TReal Math::Poly(TReal aX,const SPoly *aPoly)

    54 /**

    55 Evaluates the polynomial:

    56 {a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.

    57 

    58 

    59 @param aX    The value of the x-variable 

    60 @param aPoly A pointer to the structure containing the set of coefficients

    61              in the order: a[0], a[1], ..., a[n-1], a[n].

    62 

    63 @return The result of the evaluation.

    64 */

    65 //

    66 // Evaluate a power series in x for a P_POLY coefficient table.

    67 // Changed to use TRealX throughout the calculation

    68 //

    69 	{

    70 

    71 	const TReal *pR=(&aPoly->c[aPoly->num-1]);

    72 	TRealX r(*pR);

    73 	TRealX x(aX);

    74 	while (pR>&aPoly->c[0])

    75 		{

    76 		r*=x;

    77 		r+=*--pR;

    78 		}

    79 	return(TReal(r));

    80 	}

    81 

    82 

    83 

    84 

    85 EXPORT_C void Math::PolyX(TRealX& aY, const TRealX& aX, TInt aDegree, const TRealX *aCoeff)

    86 /**

    87 Evaluates the polynomial:

    88 {a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.

    89 

    90 @param aY      A reference containing the result. 

    91 @param aX      The value of the x-variable. 

    92 @param aDegree The degree of the polynomial (the highest power of x

    93                which is present).

    94 @param aCoeff  A pointer to a contiguous set of TRealX values containing

    95                the coefficients.

    96                They must be in the order: a[0], a[1], ..., a[n-1], a[n].

    97 */

    98 	{

    99     // Evaluate a polynomial with TRealX argument and TRealX coefficients.

   100     // Return a TRealX result.

   101 

   102 	const TRealX *pC=aCoeff+aDegree;

   103 	aY=*pC;

   104 	while(aDegree--)

   105 		{

   106 		aY*=aX;

   107 		aY+=*--pC;

   108 		}

   109 	}

   110 #endif