add spherical_coordinate

README.md

@@ -151,7 +151,7 @@ These examples incubate dotSCAD and dotSCAD refactors these examples. See [examp
 - [util/slice](https://openhome.cc/eGossip/OpenSCAD/lib3x-slice.html)
 - [util/some](https://openhome.cc/eGossip/OpenSCAD/lib3x-some.html)
 - [util/sort](https://openhome.cc/eGossip/OpenSCAD/lib3x-sort.html)
-- util/spherical_coordinate
+- [util/spherical_coordinate](https://openhome.cc/eGossip/OpenSCAD/lib3x-spherical_coordinate.html)
 - [util/sub_str](https://openhome.cc/eGossip/OpenSCAD/lib3x-sub_str.html)
 - [util/split_str](https://openhome.cc/eGossip/OpenSCAD/lib3x-split_str.html)
 - [util/sum](https://openhome.cc/eGossip/OpenSCAD/lib3x-sum.html)

docs/lib3x-spherical_coordinate.md

@@ -0,0 +1,19 @@
+# spherical_coordinate
+
+Converts from Cartesian to Polar coordinates. It returns `[radius, theta, phi]`.
+
+**Since:** 3.0
+
+## Parameters
+
+- `point` : The Cartesian coordinates of a point.
+
+## Examples
+
+    use <util/spherical_coordinate.scad>;
+    
+	coord = spherical_coordinate([100, 100, 100]);
+	r = round(coord[0]);
+	theta = round(coord[1]);
+	phi = round(coord[2]);
+    assert([r, theta, phi] ==  [173, 45, 35]);  

src/util/spherical_coordinate.scad

@@ -1,3 +1,13 @@
+/**
+* spherical_coordinate.scad
+*
+* @copyright Justin Lin, 2020
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib3x-spherical_coordinate.html
+*
+**/ 
+
 function spherical_coordinate(point) = 
     // mathematics [r, theta, phi]
     [