Eli Hughes / CMSIS_DSP_401

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ControllerFunctions/arm_sin_cos_f32.c@0:3d9c67d97d6f, 2014-07-28 (annotated)

Committer:
emh203
Date:
Mon Jul 28 15:03:15 2014 +0000
Revision:
0:3d9c67d97d6f
1st working commit.   Had to remove arm_bitreversal2.s     arm_cfft_f32.c and arm_rfft_fast_f32.c.    The .s will not assemble.      For now I removed these functions so we could at least have a library for the other functions.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emh203 0:3d9c67d97d6f 1 /* ----------------------------------------------------------------------
emh203 0:3d9c67d97d6f 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emh203 0:3d9c67d97d6f 3 *
emh203 0:3d9c67d97d6f 4 * $Date: 12. March 2014
emh203 0:3d9c67d97d6f 5 * $Revision: V1.4.3
emh203 0:3d9c67d97d6f 6 *
emh203 0:3d9c67d97d6f 7 * Project: CMSIS DSP Library
emh203 0:3d9c67d97d6f 8 * Title: arm_sin_cos_f32.c
emh203 0:3d9c67d97d6f 9 *
emh203 0:3d9c67d97d6f 10 * Description: Sine and Cosine calculation for floating-point values.
emh203 0:3d9c67d97d6f 11 *
emh203 0:3d9c67d97d6f 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emh203 0:3d9c67d97d6f 13 *
emh203 0:3d9c67d97d6f 14 * Redistribution and use in source and binary forms, with or without
emh203 0:3d9c67d97d6f 15 * modification, are permitted provided that the following conditions
emh203 0:3d9c67d97d6f 16 * are met:
emh203 0:3d9c67d97d6f 17 * - Redistributions of source code must retain the above copyright
emh203 0:3d9c67d97d6f 18 * notice, this list of conditions and the following disclaimer.
emh203 0:3d9c67d97d6f 19 * - Redistributions in binary form must reproduce the above copyright
emh203 0:3d9c67d97d6f 20 * notice, this list of conditions and the following disclaimer in
emh203 0:3d9c67d97d6f 21 * the documentation and/or other materials provided with the
emh203 0:3d9c67d97d6f 22 * distribution.
emh203 0:3d9c67d97d6f 23 * - Neither the name of ARM LIMITED nor the names of its contributors
emh203 0:3d9c67d97d6f 24 * may be used to endorse or promote products derived from this
emh203 0:3d9c67d97d6f 25 * software without specific prior written permission.
emh203 0:3d9c67d97d6f 26 *
emh203 0:3d9c67d97d6f 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
emh203 0:3d9c67d97d6f 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
emh203 0:3d9c67d97d6f 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
emh203 0:3d9c67d97d6f 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
emh203 0:3d9c67d97d6f 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
emh203 0:3d9c67d97d6f 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
emh203 0:3d9c67d97d6f 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
emh203 0:3d9c67d97d6f 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
emh203 0:3d9c67d97d6f 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
emh203 0:3d9c67d97d6f 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
emh203 0:3d9c67d97d6f 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
emh203 0:3d9c67d97d6f 38 * POSSIBILITY OF SUCH DAMAGE.
emh203 0:3d9c67d97d6f 39 * -------------------------------------------------------------------- */
emh203 0:3d9c67d97d6f 40
emh203 0:3d9c67d97d6f 41 #include "arm_math.h"
emh203 0:3d9c67d97d6f 42 #include "arm_common_tables.h"
emh203 0:3d9c67d97d6f 43
emh203 0:3d9c67d97d6f 44 /**
emh203 0:3d9c67d97d6f 45 * @ingroup groupController
emh203 0:3d9c67d97d6f 46 */
emh203 0:3d9c67d97d6f 47
emh203 0:3d9c67d97d6f 48 /**
emh203 0:3d9c67d97d6f 49 * @defgroup SinCos Sine Cosine
emh203 0:3d9c67d97d6f 50 *
emh203 0:3d9c67d97d6f 51 * Computes the trigonometric sine and cosine values using a combination of table lookup
emh203 0:3d9c67d97d6f 52 * and linear interpolation.
emh203 0:3d9c67d97d6f 53 * There are separate functions for Q31 and floating-point data types.
emh203 0:3d9c67d97d6f 54 * The input to the floating-point version is in degrees while the
emh203 0:3d9c67d97d6f 55 * fixed-point Q31 have a scaled input with the range
emh203 0:3d9c67d97d6f 56 * [-1 0.9999] mapping to [-180 +180] degrees.
emh203 0:3d9c67d97d6f 57 *
emh203 0:3d9c67d97d6f 58 * The floating point function also allows values that are out of the usual range. When this happens, the function will
emh203 0:3d9c67d97d6f 59 * take extra time to adjust the input value to the range of [-180 180].
emh203 0:3d9c67d97d6f 60 *
emh203 0:3d9c67d97d6f 61 * The implementation is based on table lookup using 360 values together with linear interpolation.
emh203 0:3d9c67d97d6f 62 * The steps used are:
emh203 0:3d9c67d97d6f 63 * -# Calculation of the nearest integer table index.
emh203 0:3d9c67d97d6f 64 * -# Compute the fractional portion (fract) of the input.
emh203 0:3d9c67d97d6f 65 * -# Fetch the value corresponding to \c index from sine table to \c y0 and also value from \c index+1 to \c y1.
emh203 0:3d9c67d97d6f 66 * -# Sine value is computed as <code> *psinVal = y0 + (fract * (y1 - y0))</code>.
emh203 0:3d9c67d97d6f 67 * -# Fetch the value corresponding to \c index from cosine table to \c y0 and also value from \c index+1 to \c y1.
emh203 0:3d9c67d97d6f 68 * -# Cosine value is computed as <code> *pcosVal = y0 + (fract * (y1 - y0))</code>.
emh203 0:3d9c67d97d6f 69 */
emh203 0:3d9c67d97d6f 70
emh203 0:3d9c67d97d6f 71 /**
emh203 0:3d9c67d97d6f 72 * @addtogroup SinCos
emh203 0:3d9c67d97d6f 73 * @{
emh203 0:3d9c67d97d6f 74 */
emh203 0:3d9c67d97d6f 75
emh203 0:3d9c67d97d6f 76 /**
emh203 0:3d9c67d97d6f 77 * @brief Floating-point sin_cos function.
emh203 0:3d9c67d97d6f 78 * @param[in] theta input value in degrees
emh203 0:3d9c67d97d6f 79 * @param[out] *pSinVal points to the processed sine output.
emh203 0:3d9c67d97d6f 80 * @param[out] *pCosVal points to the processed cos output.
emh203 0:3d9c67d97d6f 81 * @return none.
emh203 0:3d9c67d97d6f 82 */
emh203 0:3d9c67d97d6f 83
emh203 0:3d9c67d97d6f 84 void arm_sin_cos_f32(
emh203 0:3d9c67d97d6f 85 float32_t theta,
emh203 0:3d9c67d97d6f 86 float32_t * pSinVal,
emh203 0:3d9c67d97d6f 87 float32_t * pCosVal)
emh203 0:3d9c67d97d6f 88 {
emh203 0:3d9c67d97d6f 89 float32_t fract, in; /* Temporary variables for input, output */
emh203 0:3d9c67d97d6f 90 uint16_t indexS, indexC; /* Index variable */
emh203 0:3d9c67d97d6f 91 float32_t f1, f2, d1, d2; /* Two nearest output values */
emh203 0:3d9c67d97d6f 92 int32_t n;
emh203 0:3d9c67d97d6f 93 float32_t findex, Dn, Df, temp;
emh203 0:3d9c67d97d6f 94
emh203 0:3d9c67d97d6f 95 /* input x is in degrees */
emh203 0:3d9c67d97d6f 96 /* Scale the input, divide input by 360, for cosine add 0.25 (pi/2) to read sine table */
emh203 0:3d9c67d97d6f 97 in = theta * 0.00277777777778f;
emh203 0:3d9c67d97d6f 98
emh203 0:3d9c67d97d6f 99 /* Calculation of floor value of input */
emh203 0:3d9c67d97d6f 100 n = (int32_t) in;
emh203 0:3d9c67d97d6f 101
emh203 0:3d9c67d97d6f 102 /* Make negative values towards -infinity */
emh203 0:3d9c67d97d6f 103 if(in < 0.0f)
emh203 0:3d9c67d97d6f 104 {
emh203 0:3d9c67d97d6f 105 n--;
emh203 0:3d9c67d97d6f 106 }
emh203 0:3d9c67d97d6f 107 /* Map input value to [0 1] */
emh203 0:3d9c67d97d6f 108 in = in - (float32_t) n;
emh203 0:3d9c67d97d6f 109
emh203 0:3d9c67d97d6f 110 /* Calculation of index of the table */
emh203 0:3d9c67d97d6f 111 findex = (float32_t) FAST_MATH_TABLE_SIZE * in;
emh203 0:3d9c67d97d6f 112 indexS = ((uint16_t)findex) & 0x1ff;
emh203 0:3d9c67d97d6f 113 indexC = (indexS + (FAST_MATH_TABLE_SIZE / 4)) & 0x1ff;
emh203 0:3d9c67d97d6f 114
emh203 0:3d9c67d97d6f 115 /* fractional value calculation */
emh203 0:3d9c67d97d6f 116 fract = findex - (float32_t) indexS;
emh203 0:3d9c67d97d6f 117
emh203 0:3d9c67d97d6f 118 /* Read two nearest values of input value from the cos & sin tables */
emh203 0:3d9c67d97d6f 119 f1 = sinTable_f32[indexC+0];
emh203 0:3d9c67d97d6f 120 f2 = sinTable_f32[indexC+1];
emh203 0:3d9c67d97d6f 121 d1 = -sinTable_f32[indexS+0];
emh203 0:3d9c67d97d6f 122 d2 = -sinTable_f32[indexS+1];
emh203 0:3d9c67d97d6f 123
emh203 0:3d9c67d97d6f 124 Dn = 0.0122718463030f; // delta between the two points (fixed), in this case 2*pi/FAST_MATH_TABLE_SIZE
emh203 0:3d9c67d97d6f 125 Df = f2 - f1; // delta between the values of the functions
emh203 0:3d9c67d97d6f 126 temp = Dn*(d1 + d2) - 2*Df;
emh203 0:3d9c67d97d6f 127 temp = fract*temp + (3*Df - (d2 + 2*d1)*Dn);
emh203 0:3d9c67d97d6f 128 temp = fract*temp + d1*Dn;
emh203 0:3d9c67d97d6f 129
emh203 0:3d9c67d97d6f 130 /* Calculation of cosine value */
emh203 0:3d9c67d97d6f 131 *pCosVal = fract*temp + f1;
emh203 0:3d9c67d97d6f 132
emh203 0:3d9c67d97d6f 133 /* Read two nearest values of input value from the cos & sin tables */
emh203 0:3d9c67d97d6f 134 f1 = sinTable_f32[indexS+0];
emh203 0:3d9c67d97d6f 135 f2 = sinTable_f32[indexS+1];
emh203 0:3d9c67d97d6f 136 d1 = sinTable_f32[indexC+0];
emh203 0:3d9c67d97d6f 137 d2 = sinTable_f32[indexC+1];
emh203 0:3d9c67d97d6f 138
emh203 0:3d9c67d97d6f 139 Df = f2 - f1; // delta between the values of the functions
emh203 0:3d9c67d97d6f 140 temp = Dn*(d1 + d2) - 2*Df;
emh203 0:3d9c67d97d6f 141 temp = fract*temp + (3*Df - (d2 + 2*d1)*Dn);
emh203 0:3d9c67d97d6f 142 temp = fract*temp + d1*Dn;
emh203 0:3d9c67d97d6f 143
emh203 0:3d9c67d97d6f 144 /* Calculation of sine value */
emh203 0:3d9c67d97d6f 145 *pSinVal = fract*temp + f1;
emh203 0:3d9c67d97d6f 146 }
emh203 0:3d9c67d97d6f 147 /**
emh203 0:3d9c67d97d6f 148 * @} end of SinCos group
emh203 0:3d9c67d97d6f 149 */