raiden00pl commented on code in PR #9487: URL: https://github.com/apache/nuttx/pull/9487#discussion_r1221024169
########## libs/libdsp/lib_avg.c: ########## @@ -0,0 +1,67 @@ +/**************************************************************************** + * libs/libdsp/lib_avg.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <assert.h> +#include <dsp.h> +#include <string.h> + +/* Based on video explanation of Dr. Shane Ross: + * https://www.youtube.com/watch?v=HCd-leV8OkU + */ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: avg_filter + * + * Description: + * Calculate the recurring average of a signal in the time + * + * Input Parameters: + * x - current signal value + * + * Returned Value: + * Average value + * + ****************************************************************************/ + +float avg_filter(float x) +{ + static float prev_avg = 0; + static float k = 1; + float alpha; + float avg; + + alpha = (k - 1) / k; Review Comment: I suggest using the format for all `float` numbers as in other libdsp files (`1.0f`, `0.0f`). This will help to avoid situations where the compiler tries to insert `double` numbers into calculations, which means that FPU instructions are not generated. ########## libs/libdsp/lib_avg.c: ########## @@ -0,0 +1,67 @@ +/**************************************************************************** + * libs/libdsp/lib_avg.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <assert.h> +#include <dsp.h> +#include <string.h> + +/* Based on video explanation of Dr. Shane Ross: + * https://www.youtube.com/watch?v=HCd-leV8OkU + */ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: avg_filter + * + * Description: + * Calculate the recurring average of a signal in the time + * + * Input Parameters: + * x - current signal value + * + * Returned Value: + * Average value + * + ****************************************************************************/ + +float avg_filter(float x) +{ + static float prev_avg = 0; + static float k = 1; Review Comment: As mentioned earlier, it's better to pass the function's local data as a parameter, which allows the function to be reused by different users. This will require an additional function to initialize the local data for the filter (reset prev_avg and set k=1). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
