arm_variance_example_f32.c
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00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2011 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 15. December 2011 00005 * $Revision: V2.0.0 00006 * 00007 * Project: Cortex-R4 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-R4 00013 * 00014 * Version 2.0.0 2011/12/15 00015 * Final release. 00016 * 00017 * ---------------------------------------------------------------------------- */ 00018 00071 #include <math.h> 00072 #include "arm_math.h" 00073 00074 /* ---------------------------------------------------------------------- 00075 * Defines each of the tests performed 00076 * ------------------------------------------------------------------- */ 00077 #define MAX_BLOCKSIZE 32 00078 #define DELTA (0.000001f) 00079 00080 00081 /* ---------------------------------------------------------------------- 00082 * Declare I/O buffers 00083 * ------------------------------------------------------------------- */ 00084 float32_t wire1[MAX_BLOCKSIZE]; 00085 float32_t wire2[MAX_BLOCKSIZE]; 00086 float32_t wire3[MAX_BLOCKSIZE]; 00087 00088 /* ---------------------------------------------------------------------- 00089 * Test input data for Floating point Variance example for 32-blockSize 00090 * Generated by the MATLAB randn() function 00091 * ------------------------------------------------------------------- */ 00092 00093 float32_t testInput_f32[32] = 00094 { 00095 -0.432564811528221, -1.665584378238097, 0.125332306474831, 0.287676420358549, 00096 -1.146471350681464, 1.190915465642999, 1.189164201652103, -0.037633276593318, 00097 0.327292361408654, 0.174639142820925, -0.186708577681439, 0.725790548293303, 00098 -0.588316543014189, 2.183185818197101, -0.136395883086596, 0.113931313520810, 00099 1.066768211359189, 0.059281460523605, -0.095648405483669, -0.832349463650022, 00100 0.294410816392640, -1.336181857937804, 0.714324551818952, 1.623562064446271, 00101 -0.691775701702287, 0.857996672828263, 1.254001421602532, -1.593729576447477, 00102 -1.440964431901020, 0.571147623658178, -0.399885577715363, 0.689997375464345 00103 00104 }; 00105 00106 /* ---------------------------------------------------------------------- 00107 * Declare Global variables 00108 * ------------------------------------------------------------------- */ 00109 uint32_t blockSize = 32; 00110 float32_t refVarianceOut = 0.903941793931839; 00111 00112 /* ---------------------------------------------------------------------- 00113 * Variance calculation test 00114 * ------------------------------------------------------------------- */ 00115 00116 int32_t main(void) 00117 { 00118 arm_status status; 00119 float32_t mean, oneByBlockSize; 00120 float32_t variance; 00121 float32_t diff; 00122 00123 status = ARM_MATH_SUCCESS; 00124 00125 /* Calculation of mean value of input */ 00126 00127 /* x' = 1/blockSize * (x(0)* 1 + x(1) * 1 + ... + x(n-1) * 1) */ 00128 00129 /* Fill wire1 buffer with 1.0 value */ 00130 arm_fill_f32(1.0, wire1, blockSize); 00131 00132 /* Calculate the dot product of wire1 and wire2 */ 00133 /* (x(0)* 1 + x(1) * 1 + ...+ x(n-1) * 1) */ 00134 arm_dot_prod_f32(testInput_f32, wire1, blockSize, &mean); 00135 00136 /* Calculation of 1/blockSize */ 00137 oneByBlockSize = 1.0 / (blockSize); 00138 00139 /* 1/blockSize * (x(0)* 1 + x(1) * 1 + ... + x(n-1) * 1) */ 00140 arm_mult_f32(&mean, &oneByBlockSize, &mean, 1); 00141 00142 00143 /* Calculation of variance value of input */ 00144 00145 /* (1/blockSize) * (x(0) - x') * (x(0) - x') + (x(1) - x') * (x(1) - x') + ... + (x(n-1) - x') * (x(n-1) - x') */ 00146 00147 /* Fill wire2 with mean value x' */ 00148 arm_fill_f32(mean, wire2, blockSize); 00149 00150 /* wire3 contains (x-x') */ 00151 arm_sub_f32(testInput_f32, wire2, wire3, blockSize); 00152 00153 /* wire2 contains (x-x') */ 00154 arm_copy_f32(wire3, wire2, blockSize); 00155 00156 /* (x(0) - x') * (x(0) - x') + (x(1) - x') * (x(1) - x') + ... + (x(n-1) - x') * (x(n-1) - x') */ 00157 arm_dot_prod_f32(wire2, wire3, blockSize, &variance); 00158 00159 /* Calculation of 1/blockSize */ 00160 oneByBlockSize = 1.0 / (blockSize - 1); 00161 00162 /* Calculation of variance */ 00163 arm_mult_f32(&variance, &oneByBlockSize, &variance, 1); 00164 00165 /* absolute value of difference between ref and test */ 00166 diff = fabsf(refVarianceOut - variance); 00167 00168 /* Comparison of variance value with reference */ 00169 if(diff > DELTA) 00170 { 00171 status = ARM_MATH_TEST_FAILURE; 00172 } 00173 00174 if( status != ARM_MATH_SUCCESS) 00175 { 00176 while(1); 00177 } 00178 } 00179
