Iterate through values of a list every n seconds in order to update a stimulus parameter

[rsatapat]

Hi,
I would like to iterate through the values of a list of angles [0, 45, 90....] in order to update and angle parameter of DrawGratings (workflow attached) every 5 seconds.

This felt like a failry trivial problem initially but its strangely unintuitive in the context reactive programming. What is the simplest means of achieving this?

[bruno-f-cruz]

Think of a list as something you can "unroll" into a sequence of inner values with Merge.

[rsatapat]

Great, that worked! I ended up using this pattern:

I must say Merge here is throwing me for a loop. I don't quite understand how it works in this case given the definition

Could you explain a bit more? Apologies if this isn't the right place for this discussion.

[glopesdev]

@rsatapat does it work if you connect ParameterRange directly to Zip?

I would expect that to be enough, so no need for ToList or Merge.

[glopesdev]

I must say Merge here is throwing me for a loop. I don't quite understand how it works in this case given the definition

About this comment, in this case instead of passing multiple input sequences to Merge, you were passing a sequence of lists. When each list arrives, Merge subscribes to it to get its elements and emits them.

If your original sequence happens to have only one list, the result is identical to simply "unfolding" or "flattening" that list. If the sequence contains multiple lists, they will be unfolded in order of their arrival, which can be asynchronous.

We could perhaps introduce a brief discussion on this overload for enumerable-like objects on the article for Merge.

[rsatapat]

@rsatapat does it work if you connect ParameterRange directly to Zip?

I would expect that to be enough, so no need for ToList or Merge.

Yes, this does work.

[banchan86]

Hi @rsatapat! I am just reopening discussions that were closed so that they would be easier for people with similar questions to find in the future (unfortunately, GitHub defaults to only showing/searching for open discussions). Please continue to mark questions as answered, though!

[rsatapat]

Ah! I see, my bad. Thanks!