What is the appropriate Create ML data shape for my use case?

I'm taking a first swing at training a Core ML model using Create ML. I'm feeling a little out of my depth on a couple of first principles, so I'm hoping someone has some good advice.

Here's my task — I have user input for a drawing that is basically an Array<CGPoint> representing the user's touch locations in series. I want to be able to classify the drawing from a limited number of shapes (let's say "ellipse", "triangle", "rectangle").

In the Create ML app, I'm having difficulty figuring out how to provide my training data in a format it likes or will understand. As it stands right now, I have a CSV file representing an individual drawing, that is just the exported CGPoints, with X and Y as columns and each row representing a point. I have a file structure with folders labeled "ellipse", "triangle", "rectangle", each containing a number of CSV files representing individual drawings.

It seems like Create ML, to work with tabular data, wants me to provide a target (like "triangle") for each row. But that doesn't make sense to me because these values only represent "triangle" when taken in aggregate.

So I started looking at providing tabular data where the number of dimensions is greater than 2, and kind of came up short. I see that the CoreML library has some representation of multi-dimensional arrays, but I'm feeling like I must be missing some really obvious thing that would allow me to train a model using Create ML.

Does anybody have any suggestions on how to shape my data so that Create ML can ingest and train on it? I can move the data into any format/shape required. How can I take a series of x and y points and tell Create ML "this one's a triangle, this one's an ellipse, etc..."

Thanks!
As far as I understand your post, I'd approach and try it in the CreateML in the following way:
CGPoint is a struct and can be initialized with doubles or ints or cgfloats. Assuming double, I would suggest that you create a column for touch locations as X1 ,Y1, X2, Y2, Y3, Y4 in series, and last column as your target (ellipse, triangle, rectangle). Each row will be your series of touches and the number of columns will be equal to the longest of your series. The shorter series can have 0 in unused columns.
What is the appropriate Create ML data shape for my use case?
 
 
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