Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I How does one make an Amplitude vs. Frequency plot?

  1. Nov 19, 2017 #1
    I am working on homework for a physics lab course and I am asked to write a python function which will produce an amplitude v.s frequency plot. In a previous problem I wrote a function which simulates data from a sine wave in the form of a time series; the new function should be able to take this data as input and produce a plot.

    I am somewhat at a loss as to where to begin with this problem. I have worked some with amplitude vs frequency plots in the lab, but I haven't been asked to produce one before and after a couple hours I still don't have a starting point.

    To be clear, I'm not asking for programming advice, I'll figure out the code after I know what I'm doing conceptually.

    I have calculated ∆v, the frequency resolution which depends on the sampling frequency and number of data points taken but I am stuck on this: given a set of data points from a sine wave, how do I extract the amplitude of each frequency component?

    Sorry if the language used here is somewhat unclear, I will happily clarify anything doesn't make sense above.
  2. jcsd
  3. Nov 19, 2017 #2


    Staff: Mentor

  4. Nov 20, 2017 #3
    Yes, it turns out that I just needed to work the standard scipy fft function into my own function and configure it to accept a time series array as input.

    Thanks for your reply, turns out I was just overcomplicating things by trying to write a function to plot amplitude vs. frequency from scratch.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted