ENH: give me a scissor or apply Function.clip and Function.crop

[Gui-FernandesBR]

Is your feature request related to a problem? Please describe.

Mutating Function objects is magical because sometimes we need to do some particular operations with them.
This issue requests two new methods to create new Function objects from other array-based Function objects.

Describe the solution you'd like

Please implement the following:

• Function.clip : limits the y_array to a certain range, for instance, limit the sin function to be constrained between -1 an 1. This should delete any datapoint with the y value out of the range.
• Function.crop : limits the x_array to a certain range, for instance, limit the domain of a R1->R1 function to be limited by x=0 and x=1. This should delete any datapoint with the x values out of the range.

Some considerations:

• The methods should take the array source of the Function, remove the undesired data, return
• Once we remove data from the array and recreate a function object, all the interpolation coefficients will be recalculated. Should that be a problem?

I'm not sure how we would do (if possible) the same operations in non array-based Functions, so I'm leaving them out of the scope here.

Additional context

• numpy.clip
• https://stackoverflow.com/questions/43463523/center-crop-a-numpy-array
• This is already an implementation that can be used:

  RocketPy/rocketpy/Function.py

  Line 630 in d552093

  def crop(self, domain):

[Rickisterr]

Good day, I was wondering if this issue is still under consideration and if so, may I work on it?

[Gui-FernandesBR]

Good day, I was wondering if this issue is still under consideration and if so, may I work on it?

yes it is, but there's a lot already done here: https://github.com/RocketPy-Team/RocketPy/tree/enh/liq

Can you openup a PR?

[Rickisterr]

understood; then I will refer to and use the linked branch's implementation and finish this feature up and submit a PR as soon as I finish

Also, for further clarification, the methods should also clip the functions themselves for when source is a callable lambda function as well, right? Not just when it has a set of discrete values that are to be clipped?

Thank you!

[Gui-FernandesBR]

understood; then I will refer to and use the linked branch's implementation and finish this feature up and submit a PR as soon as I finish

Also, for further clarification, the methods should also clip the functions themselves for when source is a callable lambda function as well, right? Not just when it has a set of discrete values that are to be clipped?

Thank you!

yes they should.

[Rickisterr]

Good day, I just wanted to notify that I have opened up a PR regarding this. Thank you so much!

[Gui-FernandesBR]

Good day, I just wanted to notify that I have opened up a PR regarding this. Thank you so much!

Amazing work, @Rickisterr !!

[Rickisterr]

Thank you so much! I really appreciate all the help and being able to work on this and hope I can contribute even more!

[Gui-FernandesBR]

Thank you so much! I really appreciate all the help and being able to work on this and hope I can contribute even more!

If you want to pick another open issue to work on, please feel free to do so.
I believe your PR should be merged son, the review will probably be quite smooth.