Changeset 2623 in lmdz_wrf for trunk/tools

Timestamp:

Jun 22, 2019, 9:03:58 PM (6 years ago)

Author:

lfita

Message:

Adding:

• `angle_vectors2D': Angle between two vectors with sign

File:

• trunk/tools/geometry_tools.py (modified) (2 diffs)

trunk/tools/geometry_tools.py

@@ -24 +24 @@
 ####### Contents:
 # add_secpolygon_list: Function to add a range of points of a polygon into a list
+# angle_vectors2D: Angle between two vectors with sign
 # cut_between_[x/y]polygon: Function to cut a polygon between 2 given value of the [x/y]-axis
 # cut_[x/y]polygon: Function to cut a polygon from a given value of the [x/y]-axis
@@ -277 +278 @@
     fname = 'mod_vec'
 
-    mod = np.sqrt(vec[0]*vec[0] + vec[1]*vec[1])
+    v = np.array(vec, dtype=np.float)
+    mod = np.sqrt(v[0]*v[0] + v[1]*v[1])
 
     return mod
 
-print mod_vec([1., 1.])
-quit()
-
 def angle_vectors2D(veca, vecb):
-    """ Angle between two vectors
+    """ Angle between two vectors with sign
+        FROM: https://stackoverflow.com/questions/5188561/signed-angle-between-two-3d-vectors-with-same-origin-within-the-same-plane
       veca: angle A [ya, xa]
       vecb: angle B [yb, xb]
       NOTE: angle from A to B
     >>> angle_vectors2D([1.,0.], [0.,1.])
-    
+    1.57079632679
+    >>> angle_vectors2D([0.,1.], [1.,0.])
+    1.57079632679
     """
     fname = 'angle_vectors2D'
 
-    moda = mod_vec(veca)
-    modb = mod_vec(vecb)
-
-    return alpha
+    v1 = np.array(veca, dtype=np.float)
+    v2 = np.array(vecb, dtype=np.float)
+
+    moda = mod_vec(v1)
+    modb = mod_vec(v2)
+    modab = mod_vec(v1*v2)
+
+    vc = np.cross(v1,v2)
+    theta = np.arcsin(vc/(moda*modb))
+
+    # Without sign
+    #alpha = np.arccos(modab/(moda*modb))
+
+    return theta
+
+print angle_vectors2D([1.,0.], [0.,1.])
+print angle_vectors2D([0.,1.], [1.,0.])
+
+quit()
 
 def max_coords_poly(polygon):