CMSIS DSP Software Library: arm_variance_example_f32.c Source File Main Page Modules Data Structures Files Examples File List Globals arm_variance_example_f32.c Go to the documentation of this file.00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2010 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 29. November 2010 00005 * $Revision: V1.0.3 00006 * 00007 * Project: CMSIS DSP Library 00008 * Title: arm_variance_example_f32.c 00009 * 00010 * Description: Example code demonstrating variance calculation of input sequence. 00011 * 00012 * Target Processor: Cortex-M4/Cortex-M3 00013 * 00014 * 00015 * Version 1.0.3 2010/11/29 00016 * Re-organized the CMSIS folders and updated documentation. 00017 * 00018 * Version 1.0.1 2010/10/05 KK 00019 * Production release and review comments incorporated. 00020 * 00021 * Version 1.0.0 2010/09/20 KK 00022 * Production release and review comments incorporated. 00023 * ------------------------------------------------------------------- */ 00024 00077 #include <math.h> 00078 #include "arm_math.h" 00079 00080 /* ---------------------------------------------------------------------- 00081 * Defines each of the tests performed 00082 * ------------------------------------------------------------------- */ 00083 #define MAX_BLOCKSIZE 32 00084 #define DELTA (0.000001f) 00085 00086 00087 /* ---------------------------------------------------------------------- 00088 * Declare I/O buffers 00089 * ------------------------------------------------------------------- */ 00090 float32_t wire1[MAX_BLOCKSIZE]; 00091 float32_t wire2[MAX_BLOCKSIZE]; 00092 float32_t wire3[MAX_BLOCKSIZE]; 00093 00094 /* ---------------------------------------------------------------------- 00095 * Test input data for Floating point Variance example for 32-blockSize 00096 * Generated by the MATLAB randn() function 00097 * ------------------------------------------------------------------- */ 00098 00099 float32_t testInput_f32[32] = 00100 { 00101 -0.432564811528221, -1.665584378238097, 0.125332306474831, 0.287676420358549, 00102 -1.146471350681464, 1.190915465642999, 1.189164201652103, -0.037633276593318, 00103 0.327292361408654, 0.174639142820925, -0.186708577681439, 0.725790548293303, 00104 -0.588316543014189, 2.183185818197101, -0.136395883086596, 0.113931313520810, 00105 1.066768211359189, 0.059281460523605, -0.095648405483669, -0.832349463650022, 00106 0.294410816392640, -1.336181857937804, 0.714324551818952, 1.623562064446271, 00107 -0.691775701702287, 0.857996672828263, 1.254001421602532, -1.593729576447477, 00108 -1.440964431901020, 0.571147623658178, -0.399885577715363, 0.689997375464345 00109 00110 }; 00111 00112 /* ---------------------------------------------------------------------- 00113 * Declare Global variables 00114 * ------------------------------------------------------------------- */ 00115 uint32_t blockSize = 32; 00116 float32_t refVarianceOut = 0.903941793931839; 00117 00118 /* ---------------------------------------------------------------------- 00119 * Variance calculation test 00120 * ------------------------------------------------------------------- */ 00121 00122 int32_t main(void) 00123 { 00124 arm_status status; 00125 float32_t mean, oneByBlockSize; 00126 float32_t variance; 00127 float32_t diff; 00128 00129 status = ARM_MATH_SUCCESS; 00130 00131 /* Calculation of mean value of input */ 00132 00133 /* x' = 1/blockSize * (x(0)* 1 + x(1) * 1 + ... + x(n-1) * 1) */ 00134 00135 /* Fill wire1 buffer with 1.0 value */ 00136 arm_fill_f32(1.0, wire1, blockSize); 00137 00138 /* Calculate the dot product of wire1 and wire2 */ 00139 /* (x(0)* 1 + x(1) * 1 + ...+ x(n-1) * 1) */ 00140 arm_dot_prod_f32(testInput_f32, wire1, blockSize, &mean); 00141 00142 /* Calculation of 1/blockSize */ 00143 oneByBlockSize = 1.0 / (blockSize); 00144 00145 /* 1/blockSize * (x(0)* 1 + x(1) * 1 + ... + x(n-1) * 1) */ 00146 arm_mult_f32(&mean, &oneByBlockSize, &mean, 1); 00147 00148 00149 /* Calculation of variance value of input */ 00150 00151 /* (1/blockSize) * (x(0) - x') * (x(0) - x') + (x(1) - x') * (x(1) - x') + ... + (x(n-1) - x') * (x(n-1) - x') */ 00152 00153 /* Fill wire2 with mean value x' */ 00154 arm_fill_f32(mean, wire2, blockSize); 00155 00156 /* wire3 contains (x-x') */ 00157 arm_sub_f32(testInput_f32, wire2, wire3, blockSize); 00158 00159 /* wire2 contains (x-x') */ 00160 arm_copy_f32(wire3, wire2, blockSize); 00161 00162 /* (x(0) - x') * (x(0) - x') + (x(1) - x') * (x(1) - x') + ... + (x(n-1) - x') * (x(n-1) - x') */ 00163 arm_dot_prod_f32(wire2, wire3, blockSize, &variance); 00164 00165 /* Calculation of 1/blockSize */ 00166 oneByBlockSize = 1.0 / (blockSize - 1); 00167 00168 /* Calculation of variance */ 00169 arm_mult_f32(&variance, &oneByBlockSize, &variance, 1); 00170 00171 /* absolute value of difference between ref and test */ 00172 diff = fabsf(refVarianceOut - variance); 00173 00174 /* Comparison of variance value with reference */ 00175 if(diff > DELTA) 00176 { 00177 status = ARM_MATH_TEST_FAILURE; 00178 } 00179 00180 if( status != ARM_MATH_SUCCESS) 00181 { 00182 while(1); 00183 } 00184 } 00185  All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Defines Generated on Mon Nov 29 2010 17:19:57 for CMSIS DSP Software Library by  1.7.2