Diff: cmsis_dsp/FastMathFunctions/arm_sin_f32.c

Revision:

5:3762170b6d4d

Parent:

3:7a284390b0ce

--- a/cmsis_dsp/FastMathFunctions/arm_sin_f32.c	Mon Jun 23 09:30:09 2014 +0100
+++ b/cmsis_dsp/FastMathFunctions/arm_sin_f32.c	Fri Nov 20 08:45:18 2015 +0000
@@ -1,24 +1,24 @@
-/* ----------------------------------------------------------------------    
-* Copyright (C) 2010-2013 ARM Limited. All rights reserved.    
-*    
-* $Date:        17. January 2013
-* $Revision: 	V1.4.1
-*    
-* Project: 	    CMSIS DSP Library    
-* Title:		arm_sin_f32.c    
-*    
-* Description:	Fast sine calculation for floating-point values.   
-*    
+/* ----------------------------------------------------------------------
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
+*
+* $Date:        21. September 2015
+* $Revision:    V.1.4.5 a
+*
+* Project:      CMSIS DSP Library
+* Title:        arm_sin_f32.c
+*
+* Description:  Fast sine calculation for floating-point values.
+*
 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
-*  
-* Redistribution and use in source and binary forms, with or without 
+*
+* Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
-*     the documentation and/or other materials provided with the 
+*     the documentation and/or other materials provided with the
 *     distribution.
 *   - Neither the name of ARM LIMITED nor the names of its contributors
 *     may be used to endorse or promote products derived from this
@@ -27,7 +27,7 @@
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
-* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
@@ -35,189 +35,60 @@
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-* POSSIBILITY OF SUCH DAMAGE. 
+* POSSIBILITY OF SUCH DAMAGE.
 * -------------------------------------------------------------------- */
 
 #include "arm_math.h"
-
-/**    
- * @ingroup groupFastMath    
- */
+#include "arm_common_tables.h"
+#include <math.h>
 
-/**    
- * @defgroup sin Sine    
- *    
- * Computes the trigonometric sine function using a combination of table lookup   
- * and cubic interpolation.  There are separate functions for   
- * Q15, Q31, and floating-point data types.   
- * The input to the floating-point version is in radians while the   
- * fixed-point Q15 and Q31 have a scaled input with the range   
- * [0 +0.9999] mapping to [0 2*pi).  The fixed-point range is chosen so that a
- * value of 2*pi wraps around to 0.
- *   
- * The implementation is based on table lookup using 256 values together with cubic interpolation.   
- * The steps used are:   
- *  -# Calculation of the nearest integer table index   
- *  -# Fetch the four table values a, b, c, and d     
- *  -# Compute the fractional portion (fract) of the table index.   
- *  -# Calculation of wa, wb, wc, wd    
- *  -# The final result equals <code>a*wa + b*wb + c*wc + d*wd</code>   
- *   
- * where   
- * <pre>    
- *    a=Table[index-1];    
- *    b=Table[index+0];    
- *    c=Table[index+1];    
- *    d=Table[index+2];    
- * </pre>   
- * and   
- * <pre>    
- *    wa=-(1/6)*fract.^3 + (1/2)*fract.^2 - (1/3)*fract;    
- *    wb=(1/2)*fract.^3 - fract.^2 - (1/2)*fract + 1;    
- *    wc=-(1/2)*fract.^3+(1/2)*fract.^2+fract;    
- *    wd=(1/6)*fract.^3 - (1/6)*fract;    
- * </pre>    
- */
-
-/**    
- * @addtogroup sin    
- * @{    
- */
-
-
-/**   
- * \par    
- * Example code for the generation of the floating-point sine table:
- * <pre>
- * tableSize = 256;    
- * for(n = -1; n < (tableSize + 1); n++)    
- * {    
- *	sinTable[n+1]=sin(2*pi*n/tableSize);    
- * }</pre>    
- * \par    
- * where pi value is  3.14159265358979    
+/**
+ * @ingroup groupFastMath
  */
 
-static const float32_t sinTable[259] = {
-  -0.024541229009628296f, 0.000000000000000000f, 0.024541229009628296f,
-  0.049067676067352295f, 0.073564566671848297f, 0.098017141222953796f,
-  0.122410677373409270f, 0.146730467677116390f,
-  0.170961886644363400f, 0.195090323686599730f, 0.219101235270500180f,
-  0.242980182170867920f, 0.266712754964828490f, 0.290284663438797000f,
-  0.313681751489639280f, 0.336889863014221190f,
-  0.359895050525665280f, 0.382683426141738890f, 0.405241310596466060f,
-  0.427555084228515630f, 0.449611335992813110f, 0.471396744251251220f,
-  0.492898195981979370f, 0.514102756977081300f,
-  0.534997642040252690f, 0.555570244789123540f, 0.575808167457580570f,
-  0.595699310302734380f, 0.615231573581695560f, 0.634393274784088130f,
-  0.653172850608825680f, 0.671558976173400880f,
-  0.689540565013885500f, 0.707106769084930420f, 0.724247097969055180f,
-  0.740951120853424070f, 0.757208824157714840f, 0.773010432720184330f,
-  0.788346409797668460f, 0.803207516670227050f,
-  0.817584812641143800f, 0.831469595432281490f, 0.844853579998016360f,
-  0.857728600502014160f, 0.870086967945098880f, 0.881921291351318360f,
-  0.893224298954010010f, 0.903989315032958980f,
-  0.914209783077239990f, 0.923879504203796390f, 0.932992815971374510f,
-  0.941544055938720700f, 0.949528157711029050f, 0.956940352916717530f,
-  0.963776051998138430f, 0.970031261444091800f,
-  0.975702106952667240f, 0.980785250663757320f, 0.985277652740478520f,
-  0.989176511764526370f, 0.992479562759399410f, 0.995184719562530520f,
-  0.997290432453155520f, 0.998795449733734130f,
-  0.999698817729949950f, 1.000000000000000000f, 0.999698817729949950f,
-  0.998795449733734130f, 0.997290432453155520f, 0.995184719562530520f,
-  0.992479562759399410f, 0.989176511764526370f,
-  0.985277652740478520f, 0.980785250663757320f, 0.975702106952667240f,
-  0.970031261444091800f, 0.963776051998138430f, 0.956940352916717530f,
-  0.949528157711029050f, 0.941544055938720700f,
-  0.932992815971374510f, 0.923879504203796390f, 0.914209783077239990f,
-  0.903989315032958980f, 0.893224298954010010f, 0.881921291351318360f,
-  0.870086967945098880f, 0.857728600502014160f,
-  0.844853579998016360f, 0.831469595432281490f, 0.817584812641143800f,
-  0.803207516670227050f, 0.788346409797668460f, 0.773010432720184330f,
-  0.757208824157714840f, 0.740951120853424070f,
-  0.724247097969055180f, 0.707106769084930420f, 0.689540565013885500f,
-  0.671558976173400880f, 0.653172850608825680f, 0.634393274784088130f,
-  0.615231573581695560f, 0.595699310302734380f,
-  0.575808167457580570f, 0.555570244789123540f, 0.534997642040252690f,
-  0.514102756977081300f, 0.492898195981979370f, 0.471396744251251220f,
-  0.449611335992813110f, 0.427555084228515630f,
-  0.405241310596466060f, 0.382683426141738890f, 0.359895050525665280f,
-  0.336889863014221190f, 0.313681751489639280f, 0.290284663438797000f,
-  0.266712754964828490f, 0.242980182170867920f,
-  0.219101235270500180f, 0.195090323686599730f, 0.170961886644363400f,
-  0.146730467677116390f, 0.122410677373409270f, 0.098017141222953796f,
-  0.073564566671848297f, 0.049067676067352295f,
-  0.024541229009628296f, 0.000000000000000122f, -0.024541229009628296f,
-  -0.049067676067352295f, -0.073564566671848297f, -0.098017141222953796f,
-  -0.122410677373409270f, -0.146730467677116390f,
-  -0.170961886644363400f, -0.195090323686599730f, -0.219101235270500180f,
-  -0.242980182170867920f, -0.266712754964828490f, -0.290284663438797000f,
-  -0.313681751489639280f, -0.336889863014221190f,
-  -0.359895050525665280f, -0.382683426141738890f, -0.405241310596466060f,
-  -0.427555084228515630f, -0.449611335992813110f, -0.471396744251251220f,
-  -0.492898195981979370f, -0.514102756977081300f,
-  -0.534997642040252690f, -0.555570244789123540f, -0.575808167457580570f,
-  -0.595699310302734380f, -0.615231573581695560f, -0.634393274784088130f,
-  -0.653172850608825680f, -0.671558976173400880f,
-  -0.689540565013885500f, -0.707106769084930420f, -0.724247097969055180f,
-  -0.740951120853424070f, -0.757208824157714840f, -0.773010432720184330f,
-  -0.788346409797668460f, -0.803207516670227050f,
-  -0.817584812641143800f, -0.831469595432281490f, -0.844853579998016360f,
-  -0.857728600502014160f, -0.870086967945098880f, -0.881921291351318360f,
-  -0.893224298954010010f, -0.903989315032958980f,
-  -0.914209783077239990f, -0.923879504203796390f, -0.932992815971374510f,
-  -0.941544055938720700f, -0.949528157711029050f, -0.956940352916717530f,
-  -0.963776051998138430f, -0.970031261444091800f,
-  -0.975702106952667240f, -0.980785250663757320f, -0.985277652740478520f,
-  -0.989176511764526370f, -0.992479562759399410f, -0.995184719562530520f,
-  -0.997290432453155520f, -0.998795449733734130f,
-  -0.999698817729949950f, -1.000000000000000000f, -0.999698817729949950f,
-  -0.998795449733734130f, -0.997290432453155520f, -0.995184719562530520f,
-  -0.992479562759399410f, -0.989176511764526370f,
-  -0.985277652740478520f, -0.980785250663757320f, -0.975702106952667240f,
-  -0.970031261444091800f, -0.963776051998138430f, -0.956940352916717530f,
-  -0.949528157711029050f, -0.941544055938720700f,
-  -0.932992815971374510f, -0.923879504203796390f, -0.914209783077239990f,
-  -0.903989315032958980f, -0.893224298954010010f, -0.881921291351318360f,
-  -0.870086967945098880f, -0.857728600502014160f,
-  -0.844853579998016360f, -0.831469595432281490f, -0.817584812641143800f,
-  -0.803207516670227050f, -0.788346409797668460f, -0.773010432720184330f,
-  -0.757208824157714840f, -0.740951120853424070f,
-  -0.724247097969055180f, -0.707106769084930420f, -0.689540565013885500f,
-  -0.671558976173400880f, -0.653172850608825680f, -0.634393274784088130f,
-  -0.615231573581695560f, -0.595699310302734380f,
-  -0.575808167457580570f, -0.555570244789123540f, -0.534997642040252690f,
-  -0.514102756977081300f, -0.492898195981979370f, -0.471396744251251220f,
-  -0.449611335992813110f, -0.427555084228515630f,
-  -0.405241310596466060f, -0.382683426141738890f, -0.359895050525665280f,
-  -0.336889863014221190f, -0.313681751489639280f, -0.290284663438797000f,
-  -0.266712754964828490f, -0.242980182170867920f,
-  -0.219101235270500180f, -0.195090323686599730f, -0.170961886644363400f,
-  -0.146730467677116390f, -0.122410677373409270f, -0.098017141222953796f,
-  -0.073564566671848297f, -0.049067676067352295f,
-  -0.024541229009628296f, -0.000000000000000245f, 0.024541229009628296f
-};
+/**
+ * @defgroup sin Sine
+ *
+ * Computes the trigonometric sine function using a combination of table lookup
+ * and linear interpolation.  There are separate functions for
+ * Q15, Q31, and floating-point data types.
+ * The input to the floating-point version is in radians while the
+ * fixed-point Q15 and Q31 have a scaled input with the range
+ * [0 +0.9999] mapping to [0 2*pi).  The fixed-point range is chosen so that a
+ * value of 2*pi wraps around to 0.
+ *
+ * The implementation is based on table lookup using 256 values together with linear interpolation.
+ * The steps used are:
+ *  -# Calculation of the nearest integer table index
+ *  -# Compute the fractional portion (fract) of the table index.
+ *  -# The final result equals <code>(1.0f-fract)*a + fract*b;</code>
+ *
+ * where
+ * <pre>
+ *    b=Table[index+0];
+ *    c=Table[index+1];
+ * </pre>
+ */
 
+/**
+ * @addtogroup sin
+ * @{
+ */
 
-/**   
- * @brief  Fast approximation to the trigonometric sine function for floating-point data.   
- * @param[in] x input value in radians.   
- * @return  sin(x).   
+/**
+ * @brief  Fast approximation to the trigonometric sine function for floating-point data.
+ * @param[in] x input value in radians.
+ * @return  sin(x).
  */
 
 float32_t arm_sin_f32(
   float32_t x)
 {
-  float32_t sinVal, fract, in;                   /* Temporary variables for input, output */
-  int32_t index;                                 /* Index variable */
-  uint32_t tableSize = (uint32_t) TABLE_SIZE;    /* Initialise tablesize */
-  float32_t wa, wb, wc, wd;                      /* Cubic interpolation coefficients */
-  float32_t a, b, c, d;                          /* Four nearest output values */
-  float32_t *tablePtr;                           /* Pointer to table */
+  float32_t sinVal, fract, in;                           /* Temporary variables for input, output */
+  uint16_t index;                                        /* Index variable */
+  float32_t a, b;                                        /* Two nearest output values */
   int32_t n;
-  float32_t fractsq, fractby2, fractby6, fractby3, fractsqby2;
-  float32_t oneminusfractby2;
-  float32_t frby2xfrsq, frby6xfrsq;
+  float32_t findex;
 
   /* input x is in radians */
   /* Scale the input to [0 1] range from [0 2*PI] , divide input by 2*pi */
@@ -229,63 +100,34 @@
   /* Make negative values towards -infinity */
   if(x < 0.0f)
   {
-    n = n - 1;
+    n--;
   }
 
   /* Map input value to [0 1] */
   in = in - (float32_t) n;
 
   /* Calculation of index of the table */
-  index = (uint32_t) (tableSize * in);
-
-  /* fractional value calculation */
-  fract = ((float32_t) tableSize * in) - (float32_t) index;
-
-  /* Checking min and max index of table */
-  if(index < 0)
-  {
-    index = 0;
-  }
-  else if(index > 256)
-  {
-    index = 256;
+  findex = (float32_t) FAST_MATH_TABLE_SIZE * in;
+  if (findex >= 512.0f) {
+    findex -= 512.0f;
   }
 
-  /* Initialise table pointer */
-  tablePtr = (float32_t *) & sinTable[index];
+  index = ((uint16_t)findex) & 0x1ff;
 
-  /* Read four nearest values of input value from the sin table */
-  a = tablePtr[0];
-  b = tablePtr[1];
-  c = tablePtr[2];
-  d = tablePtr[3];
+  /* fractional value calculation */
+  fract = findex - (float32_t) index;
 
-  /* Cubic interpolation process */
-  fractsq = fract * fract;
-  fractby2 = fract * 0.5f;
-  fractby6 = fract * 0.166666667f;
-  fractby3 = fract * 0.3333333333333f;
-  fractsqby2 = fractsq * 0.5f;
-  frby2xfrsq = (fractby2) * fractsq;
-  frby6xfrsq = (fractby6) * fractsq;
-  oneminusfractby2 = 1.0f - fractby2;
-  wb = fractsqby2 - fractby3;
-  wc = (fractsqby2 + fract);
-  wa = wb - frby6xfrsq;
-  wb = frby2xfrsq - fractsq;
-  sinVal = wa * a;
-  wc = wc - frby2xfrsq;
-  wd = (frby6xfrsq) - fractby6;
-  wb = wb + oneminusfractby2;
+  /* Read two nearest values of input value from the sin table */
+  a = sinTable_f32[index];
+  b = sinTable_f32[index+1];
 
-  /* Calculate sin value */
-  sinVal = (sinVal + (b * wb)) + ((c * wc) + (d * wd));
+  /* Linear interpolation process */
+  sinVal = (1.0f-fract)*a + fract*b;
 
   /* Return the output value */
   return (sinVal);
-
 }
 
-/**    
- * @} end of sin group    
+/**
+ * @} end of sin group
  */