[ENH] Adds ability to calculate dense microarray expression

[gshafiei]

Previously the microarray expression was calculated by matching samples to ROIs in the image. Therefore, the output would have some ROIs with missing expression. The new version has the ability to match all ROIs to closest samples, such that all ROIs will have have at least one assigned sample. Thus, the output microarray expression will be a dense matrix. In order to output the dense microarray expression by matching ROIs to samples, the user has to add "dense=True" as an additional input argument to the function "get_expression_data()".

[rmarkello]

Hi @gshafiei! I am so sorry that I haven't commented on this, yet! It's been a very busy month, but that's no excuse for leaving you in the dark like this.

Thank you so much for this contribution! ✨ I will try and do a detailed review of this pull request within the next week and get back to you with any suggestions. In the interim, let me know if there is anything in particular you want me to focus on or that you might be worried about! From a quick scan I can tell you it looks great 🙂 Expect to hear back from me soon with more, though.

[rmarkello]

Hi again! I just went through this and it looks great to me. There are a few minor tweaks that I might make at a later date after doing a more thorough check for speed, but I'm going to go ahead and merge this in for now. Thanks so much for this contribution!