Way to create sets of parallel lines with proper point provenance #18

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opened 2023-01-01 18:27:32 +00:00 by zyxw59 · 1 comment

zyxw59 commented

2023-01-01 18:27:32 +00:00

(Migrated from github.com)

Currently, if you define some grid lines and points like so:

N = dir 0;
E = dir 90;

n0 = (0 * N) >> E;
e0 = (0 * E) >> N;
e1 = (1 * E) >> N;
e2 = (2 * E) >> N;

point n0e0 = n0 & e0;
point n0e1 = n0 & e1;
point n0e2 = n0 & e2;

points n0e0, n0e1, and n0e2 are not treated as collinear, because lines created with the >> operator don't have any provenance associated with them.

Possible ways to resolve this:

Dedicated operator for generating grids
Giving some provenance to lines created with the >> operator, such that all points created from intersections with that line are associated with that line
Giving some provenance to vectors (which would be unaffected by scalar multiplication!) and have lines created with the >> operator inherit that provenance.

Currently, if you define some grid lines and points like so: ``` N = dir 0; E = dir 90; n0 = (0 * N) >> E; e0 = (0 * E) >> N; e1 = (1 * E) >> N; e2 = (2 * E) >> N; point n0e0 = n0 & e0; point n0e1 = n0 & e1; point n0e2 = n0 & e2; ``` points `n0e0`, `n0e1`, and `n0e2` are not treated as collinear, because lines created with the `>>` operator don't have any provenance associated with them. Possible ways to resolve this: - Dedicated operator for generating grids - Giving some provenance to lines created with the `>>` operator, such that all points created from intersections with that line are associated with that line - Giving some provenance to *vectors* (which would be unaffected by scalar multiplication!) and have lines created with the `>>` operator inherit that provenance.

zyxw59 commented

2025-06-17 17:00:14 +00:00

(Migrated from github.com)

I think the most obvious thing is to give lines provenance.

I think the most obvious thing is to give *lines* provenance.