Improvements for Line z_extreme and Subsystem lineTypes

- Line.z_extreme provides absolute z elevation of highest/lowest
  point on a line section (in direction of its wet weight).
- Subsystem.makeGeneric now can handle a list of lineType dicts
  in which case it won't make new lineType entries.
- Added a helper function for drawing a 3D box - nice for
  visualizing fairlead positions on a body.

moorpy/Catenary.py

@@ -59,7 +59,8 @@ def catenary(XF, ZF, L, EA, W, CB=0, alpha=0, HF0=0, VF0=0, Tol=0.000001, nNodes
         stiffnessBA - 2D stiffness matrix for force at B due to movement of A [N/m].
         LBot - length of line section laying on the seabed [m].
         ProfileType
-        Zextreme - extreme z coordinate of the line section (in direction of wet weight) [m].
+        Zextreme - extreme z coordinate of the line section (in direction of 
+        wet weight), relative to height of end A [m].
     
     '''
 

moorpy/helpers.py

@@ -902,6 +902,24 @@ def addToDict(dict1, dict2, key1, key2, default=None):
     dict2[key2] = val
 
 
+def drawBox(ax, r1, r2, color=[0,0,0,0.2]):
+    '''Draw a box along the x-y-z axes between two provided corner points.'''
+
+
+    ax.plot([r1[0], r2[0]], [r1[1], r1[1]], [r1[2], r1[2]], color=color) # along x
+    ax.plot([r1[0], r2[0]], [r2[1], r2[1]], [r1[2], r1[2]], color=color)
+    ax.plot([r1[0], r2[0]], [r1[1], r1[1]], [r2[2], r2[2]], color=color)
+    ax.plot([r1[0], r2[0]], [r2[1], r2[1]], [r2[2], r2[2]], color=color)
+    ax.plot([r1[0], r1[0]], [r1[1], r2[1]], [r1[2], r1[2]], color=color) # along y
+    ax.plot([r2[0], r2[0]], [r1[1], r2[1]], [r1[2], r1[2]], color=color)
+    ax.plot([r1[0], r1[0]], [r1[1], r2[1]], [r2[2], r2[2]], color=color)
+    ax.plot([r2[0], r2[0]], [r1[1], r2[1]], [r2[2], r2[2]], color=color)
+    ax.plot([r1[0], r1[0]], [r1[1], r1[1]], [r1[2], r2[2]], color=color) # along z
+    ax.plot([r1[0], r1[0]], [r2[1], r2[1]], [r1[2], r2[2]], color=color)
+    ax.plot([r2[0], r2[0]], [r1[1], r1[1]], [r1[2], r2[2]], color=color)
+    ax.plot([r2[0], r2[0]], [r2[1], r2[1]], [r1[2], r2[2]], color=color)
+
+
 def makeTower(twrH, twrRad):
     '''Sets up mesh points for visualizing a cylindrical structure (should align with RAFT eventually.'''
 

moorpy/line.py

@@ -841,6 +841,7 @@ def staticSolve(self, reset=False, tol=0.0001, profiles=0):
 
         # save other important info
         self.LBot = info["LBot"]
+        self.z_extreme = self.rA[2] + info["Zextreme"]
         self.info = info
 
         # save forces in global reference frame

moorpy/subsystem.py

@@ -129,9 +129,11 @@ def makeGeneric(self, lengths, types, suspended=0):
         lengths : list of floats
             List of each section's length. This also implies the number of
             sections.
-        types : list of dicts
-            List of lineType names for each section. These names must match
-            keys in the parent system lineTypes dictionary or the subsystem's lineTypes dictionary...
+        types : list of strings or dicts
+            List of lineType names or dicts for each section. If strings, 
+            these names must match keys in the parent system lineTypes 
+            dictionary or the subsystem's lineTypes dictionary. If dicts,
+            these dicts are referred to for each lineType (by reference).
         suspended : int
             Selector shared/suspended cases: 
             - 0 (default): end A is on the seabed,
@@ -169,7 +171,10 @@ def makeGeneric(self, lengths, types, suspended=0):
         for i in range(self.nLines):
 
             # find the specified lineType dict and save a reference to it
-            if types[i] in self.lineTypes:  # first look for the name in the subsystem
+            if type(types[i]) == dict:  # if it's a dictionary, just point to it
+                self.lineTypes[i] = types[i]
+            # otherwise we're assuming it's a string of the lineType name
+            elif types[i] in self.lineTypes:  # first look for the name in the subsystem
                 self.lineTypes[i] = self.lineTypes[types[i]]
             elif self.sys: # otherwise look in the parent system, if there is one
                 if types[i] in self.sys.lineTypes:  # first look for the name in the subsystem

moorpy/system.py

@@ -2599,7 +2599,7 @@ def getCoupledStiffnessA(self, lines_only=False, tensions=False):
         # invert matrix
         K_inv_all = np.linalg.inv(K_all)
 
-        # remove free DOFs (this corresponds to saying that the same of forces on these DOFs will remain zero)
+        # remove free DOFs (this corresponds to saying that the sum of forces on these DOFs will remain zero)
         #indices = list(range(n))                # list of DOF indices that will remain active for this step
         mask = [True]*n                         # this is a mask to be applied to the array K indices