esp32_shock/components/lis3dsh/fft_lib/dsps_wind_hann_f32.c
2024-04-27 09:15:55 +08:00

26 lines
896 B
C

// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
//
// 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
//
// http://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.
#define _USE_MATH_DEFINES
#include "inc/dsps_wind_hann.h"
#include <math.h>
void dsps_wind_hann_f32(float *window, int len)
{
float len_mult = 1 / (float)(len - 1);
for (int i = 0; i < len; i++) {
window[i] = 0.5 * (1 - cosf(i * 2 * M_PI * len_mult));
}
}