# List of points won't work

I’m working on a graphing picture where students will move points around to create a picture. I was trying to make a list of points from a table in order to compare it to the student locations. The error for list “L” says you can’t make a list of points, but I have a list of points by point names. Why?

If you’re making a list by point name, you’re still making a list of points. You’ll need to parse the coordinates first.

.x and .y could work for you here.
https://www.desmos.com/calculator/4undelj7x0

That helps answer one of my questions for comparing coordinates of points, but still doesn’t explain why list A in the Unscramble folder was valid and list L was not.U Mad Bro? Graph Unscramble

Oh that’s a calculator thing. Let me get some reasoning from one of our engineers. Maybe @eric can help?

Unless I’m missing something,
(x_13, y_13) gives you a list of three points, and then the square brackets are trying to put that list inside another list. Just lose the square brackets.

I thought I had tried that, but went back and it does work. It just doesn’t give the note that it’s a 3 element list, so I didn’t think it had, but I can work with it as a list using .x and .y. Thanks!

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Neither the list of points by name nor the list of points as deceived above by Sean will allow for much computation if at all. I think they’re actually the same thing. Which is super useful (thanks Sean!) but won’t do you any good beyond a visual. Furthermore, if you want to use it in the computation layer you’ll need the list to be of numbers only.

Each column in your table is actually a number list. You can call on those lists in CL no problem.

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Actually, they do allow for computation. A.x makes a list of the x coordinates of the list of points, A. Using the list from the tables is a helpful shortcut, as I’m trying to make a conditional. How do you reference a certain element of a list?

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Oh yeah, with .x .y, totally possible! You can reference a list item by appending the list name with [index]

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