diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_entropy_f64.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_entropy_f64.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_entropy_f64.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_entropy_f64.c new file mode 100644 index 0000000..d671791 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_entropy_f64.c @@ -0,0 +1,73 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_logsumexp_f64.c + * Description: LogSumExp + * + * $Date: 23 April 2021 + * $Revision: V1.9.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "dsp/statistics_functions.h" +#include <limits.h> +#include <math.h> + +/** + * @addtogroup Entropy + * @{ + */ + +/** + * @brief Entropy + * + * @param[in] pSrcA Array of input values. + * @param[in] blockSize Number of samples in the input array. + * @return Entropy -Sum(p ln p) + * + */ + +float64_t arm_entropy_f64(const float64_t * pSrcA, uint32_t blockSize) +{ + const float64_t *pIn; + uint32_t blkCnt; + float64_t accum, p; + + pIn = pSrcA; + blkCnt = blockSize; + + accum = 0.0; + + while(blkCnt > 0) + { + p = *pIn++; + + accum += p * log(p); + + blkCnt--; + + } + + return(-accum); +} + +/** + * @} end of Entropy group + */ |