Small update to the circular formation script (#2046)

* sigmas are in degrees now. We print all the errors correctly for logging purposes. The conversion to floats from the gvf msg has been changed since it complained for some machines.

* example added

* do not forcing a particular path

* cleaner demo flight plan. Now it also includes the gvf module

* correct usage msg

* [GVF] Example for the wiki and README

sw/ground_segment/python/gvf/README

@@ -0,0 +1,9 @@
+For details about how to employ the python scripts check the wiki entry
+https://wiki.paparazziuav.org/wiki/Module/guidance_vector_field 
+
+gvfApp draws an aircraft following the guidance vector vield, ex:
+python gvfApp 80 , draws for the aircraft with id 80.
+
+gvfFormation control several aircraft in a circular formation, ex:
+python gvfFormation ./formation/topology.txt ./formation/sigmas.txt
+./formation/ids.txt 80 10

sw/ground_segment/python/gvf/formation/ids.txt

@@ -0,0 +1 @@
+14 56 34

sw/ground_segment/python/gvf/formation/sigmas.txt

@@ -0,0 +1 @@
+0 90

sw/ground_segment/python/gvf/formation/topology.txt

@@ -0,0 +1,3 @@
+ 1  0
+-1  1
+ 0 -1

sw/ground_segment/python/gvf/gvfApp.py

@@ -18,7 +18,7 @@ class MessagesApp(wx.App):
 
 def main():
     if len(sys.argv) != 2:
-        print "Usage: gvfFormationApp id_aircraft"
+        print "Usage: gvfApp id_aircraft"
         return
     id_ac = int(sys.argv[1])
     application = MessagesApp(0, id_ac)

sw/ground_segment/python/gvf/gvfFormation.py

@@ -42,11 +42,11 @@ def message_recv(ac_id, msg):
 
         if msg.name == 'GVF':
             if int(msg.get_field(1)) == 1:
-                param = [float(x) for x in msg.get_field(3).split(',')]
-                ac.XYc[0] = param[0]
-                ac.XYc[1] = param[1]
-                ac.a = param[2]
-                ac.b = param[3]
+                param = msg.get_field(3).split(',')
+                ac.XYc[0] = float(param[0])
+                ac.XYc[1] = float(param[1])
+                ac.a = float(param[2])
+                ac.b = float(param[3])
 
         if msg.name == 'BAT':
             ac.time = float(msg.get_field(3))
@@ -86,7 +86,7 @@ def formation(B, ds, radius, k):
 
     u = -k*B.dot(error_sigma)
 
-    print list_aircraft[0].time, " ", error_sigma[0], " ", error_sigma[1]
+    print list_aircraft[0].time, " ", str(error_sigma*180.0/np.pi).replace('[','').replace(']','')
 
     i = 0
     for ac in list_aircraft:
@@ -112,7 +112,7 @@ def main():
         return
 
     B = np.loadtxt(sys.argv[1])
-    desired_sigmas = np.loadtxt(sys.argv[2])
+    desired_sigmas = np.loadtxt(sys.argv[2])*np.pi/180.0
     ids = np.loadtxt(sys.argv[3])
     radius = float(sys.argv[4])
     k = float(sys.argv[5])