Linked Questions

2answers
220 views

Is the typical implementation of low pass filter in C code actually not a typical low pass filter?

Quite often in C code you see something along the lines of: $$y = (1-a) y_{prev} + input * a$$ ..where $a$ is some small number. This equation then runs in discrete intervals at the loop rate. ...
2answers
126 views

Half Window Functions and Formulas

I am looking at implementing different window functions in an application I am making. I have found the formulas for all major symmetrical windows, however I would like to implement half windows. ...
4answers
483 views

Sequential Form of the Least Squares Estimator for Linear Least Squares Model

I'm currently working on a project in which I need to find the tilt of a surface. Let's assume I'm only concerned with a single dimension tilt (i.e. slope) to begin. I currently have the ability to ...
4answers
2k views

Why is the first value in digital first-order IIR filter impulse response not the largest?

When I create a digital first-order IIR low-pass filter with scipy (code below), I get the following coefficients: B: [ 0.1367 0.1367] A: [ 1. -0.7265] The ...
3answers
693 views

What is the name of this digital low pass filter?

I found this digital filter in code I am working on. It is a low pass filter. In the code it is called an "alpha filter", but it is not the same as the alpha filter mentioned here. I post the ...
3answers
925 views

Is there a common name for the first order IIR averaging filter?

Is there a term to describe this IIR averaging/smoothing filter? $y[n] = \alpha x[n] + (1 - \alpha) y[n - 1]$
2answers
607 views

What is the name of these simple filter algorithms?

I found some snippets of code on the internet that are really simple signal filters. Unfortunately there wasn't much info to back it up. Using Google I've found similar code, but none of it backed up ...
3answers
2k views

Is there a way to derive an FIR filter using an IIR filter?

I know there's a thread similar to this one here, but the OP is asking the reverse of what I'm trying to find here. I've done some research on the web with very few sources coming up with actual ...
1answer
1k views

How does this “simple filter” work?

I'm new to DSP, and I'm using this basic "1-pole LPF" Param Smooth filter which "smooth" param when I change it. The code is pretty simple: ...
1answer
782 views

how does this equation correspond to smoothing?

Please help me understand smoothing of data. This is a follow up to my previous question posted here. Especially the top answer by Junuxx where he says a way of smoothing a function $f(x)$ is:  f'[...
2answers
12k views

Is a leaky integrator the same thing as a low pass filter?

The equation governing a leaky integrator (according to Wikipedia at least) is $\frac{d\mathcal{O}}{dt} + A\mathcal{O}(t) = \mathcal{I}(t)$. Is a continuous-time leaky integrator thus the same ...
3answers
3k views

“Low-pass filter” in non-EE, software API contexts

I am an experienced software engineer and am working on smartphone sensors. I've taken fundamental EE classes in DSP and am trying to apply my knowledge. I believe that I understand convolution, ...