topic How to calculate position in a clockwise manner? in ArcGIS Pro Questions

How to calculate position in a clockwise manner?

Davec43 — Fri, 01 Dec 2023 16:31:29 GMT

I have data with X/Y data that plots and I'm trying to get it to look like so:

I've tried near analysis, and it gets me close but doesn't label them in a clockwise manner. Is there any geoprocessing tool or arcpy process that I'm overlooking that will accomplish this?

Re: How to calculate position in a clockwise manner?

VinceAngelo — Fri, 01 Dec 2023 17:29:51 GMT

You can write your own, but I doubt there's any general purpose tool for this.

The atan2 function takes dy & dx parameters, but that's counter-clockwise from 3-o'clock,
so you'd need to reverse the sign and rotate.

- V

Re: How to calculate position in a clockwise manner?

DanPatterson — Fri, 01 Dec 2023 21:32:01 GMT

slow week

aoi # a square array([[ 0.00, 5.00], [ 5.00, 10.00], [ 10.00, 5.00], [ 5.00, 0.00], [ 0.00, 5.00]]) def geom_angles(a, fromNorth=False): """Polyline/segment angles. Parameters ---------- a : array-like A Geo array or a list of arrays representing the polyline shapes. """ out = [] dxy = a[1:] - a[:-1] ang = np.degrees(np.arctan2(dxy[:, 1], dxy[:, 0])) if fromNorth: ang = np.mod((450.0 - ang), 360.) return ang geom_angles(aoi, fromNorth=False) # -- option 1 array([ 45.00, -45.00, -135.00, 135.00]) geom_angles(aoi, fromNorth=True) # -- option 2 array([ 45.00, 135.00, 225.00, 315.00]) cent = np.mean(aoi[:-1]) # -- now from the center of the points vals = aoi - cent # -- angles from the center vals array([[ -5.00, 0.00], [ 0.00, 5.00], [ 5.00, 0.00], [ 0.00, -5.00], [ -5.00, 0.00]]) geom_angles(vals, fromNorth=False) array([ 45.00, -45.00, -135.00, 135.00]) geom_angles(vals, fromNorth=True) array([ 45.00, 135.00, 225.00, 315.00])

Re: How to calculate position in a clockwise manner?

Davec43 — Mon, 04 Dec 2023 11:30:39 GMT

Thanks Dan!