complete redesign: use nodejs on server instead of php - documentation to be updated

nodejs/node_modules/stylus/lib/functions/tan.js

@@ -0,0 +1,28 @@
+var utils = require('../utils')
+  , nodes = require('../nodes');
+
+/**
+ * Return the tangent of the given `angle`.
+ *
+ * @param {Unit} angle
+ * @return {Unit}
+ * @api public
+ */
+
+module.exports = function tan(angle) {
+  utils.assertType(angle, 'unit', 'angle');
+
+  var radians = angle.val;
+
+  if (angle.type === 'deg') {
+    radians *= Math.PI / 180;
+  }
+
+  var m = Math.pow(10, 9);
+
+  var sin = Math.round(Math.sin(radians) * m) / m
+    , cos = Math.round(Math.cos(radians) * m) / m
+    , tan = Math.round(m * sin / cos ) / m;
+
+  return new nodes.Unit(tan, '');
+};