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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_hamming_f32.c
* Description: Floating-point (f32) Hamming window
*
* $Date: 14 December 2022
* $Revision: v1.15.0
*
* Target Processor: Cortex-M and Cortex-A cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2022 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 "arm_compiler_specific.h"
#include "dsp/window_functions.h"
#include "dsp/fast_math_functions.h"
#include <math.h>
/**
@ingroup groupWindow
*/
/**
@addtogroup WindowNormal
@{
*/
/**
@defgroup WindowHAMMING Hamming window function (42.7 dB)
*/
/**
@ingroup WindowHAMMING
*/
/**
@brief Hamming window generating function (f32).
@param[out] pDst points to the output generated window
@param[in] blockSize number of samples in the window
@par Parameters of the window
| Parameter | Value |
| ------------------------------------: | -----------------: |
| Peak sidelobe level | 42.7 dB |
| Normalized equivalent noise bandwidth | 1.3628 bins |
| 3 dB bandwidth | 1.3008 bins |
| Flatness | -1.7514 dB |
| Recommended overlap | 50 % |
*/
ARM_DSP_ATTRIBUTE void arm_hamming_f32(
float32_t * pDst,
uint32_t blockSize)
{
float32_t k = 2.0f / ((float32_t) blockSize);
float32_t w;
for(uint32_t i=0;i<blockSize;i++)
{
w = 0.54f - 0.46f * cosf (PI * i * k);
pDst[i] = w;
}
}
/**
@} end of WindowNormal group
*/
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