Minor catenary bug fixes and bath plot tweak:

- Catenary: adjustment to avoid error with never-ending recursive loop
  when solving profile of U shaped lines (by removing Tol from seabed contact).
- Catenary: fixed irregularity on node outputs of U shaped profiles. Now the
  nodes are evently distributed as expected.
- System plotting: editing optional bathymetry plotting arguments to now have
  "args_bath", a dictionary of optional arguments that go straight to the 3d
  surface plotting function to allow greater control. cmap_bath and alpha are
  now removed as separate options.

moorpy/Catenary.py

@@ -92,7 +92,7 @@ def catenary(XF, ZF, L, EA, W, CB=0, alpha=0, HF0=0, VF0=0, Tol=0.000001, nNodes
         flipFlag = False
 
     # reverse line in the solver if end A is above end B
-    if ZF < 0 and hA > Tol:  # and if end A isn't on the seabed 
+    if ZF < 0 and hA > 0:  # and if end A isn't on the seabed 
         #CB = -max(0, -CB) - ZF + XF*np.tan(np.radians(alpha))
         hA, hB = hB, hA
         ZF = -ZF
@@ -648,18 +648,19 @@ def step_func_U(X, args, Y, info, Ytarget, err, tols, iter, maxIter):
             X, Y, infoU = dsolve2(eval_func_U, [X1_0], step_func=step_func_U, ytol=0.25*Tol, stepfac=1, maxIter=20, a_max=1.2, display=0)
             X1 = X[0]
             X2 = XF-X1
-            nNodes1 = int(L1/L*nNodes + 0.5)  # set number of nodes in the first line proportionally to its length, rounded.
+            nNodes1 = int(L1/L*(nNodes-1) + 0.5) + 1  # set number of nodes in the first line by trying to keep original segment length
 
             # call one more time to get final values
             (fAH1, fAV1, fBH1, fBV1, info1) = catenary(X1, Z1, L1, EA, W, CB=Z1, alpha=0, Tol=0.5*Tol, MaxIter=MaxIter, plots=plots, nNodes=nNodes1)
-            (fAH2, fAV2, fBH2, fBV2, info2) = catenary(X2, Z2, L2, EA, W, CB=0, alpha=0, Tol=0.5*Tol, MaxIter=MaxIter, plots=plots, nNodes=nNodes-nNodes1)
+            (fAH2, fAV2, fBH2, fBV2, info2) = catenary(X2, Z2, L2, EA, W, CB=0, alpha=0, Tol=0.5*Tol, MaxIter=MaxIter, plots=plots, nNodes=nNodes-nNodes1+1)
 
             if plots > 0 or (info1['error'] and info2['error']):
 
-                s  = np.hstack([ info1["s" ] , info2["s" ]+L1 ])
-                Xs = np.hstack([ info1["X" ] , info2["X" ]+X1 ])
-                Zs = np.hstack([ info1["Z" ] , info2["Z" ]+Z1 ])
-                Te = np.hstack([ info1["Te"] , info2["Te"]    ])
+                # concatenate nodal values (removing duplicate at the end nodes where they connect)
+                s  = np.hstack([ info1["s" ] , info2["s" ][1:]+L1 ])
+                Xs = np.hstack([ info1["X" ] , info2["X" ][1:]+X1 ])
+                Zs = np.hstack([ info1["Z" ] , info2["Z" ][1:]+Z1 ])
+                Te = np.hstack([ info1["Te"] , info2["Te"][1:]    ])
 
                 # re-reverse line distributed data back to normal if applicable
                 '''
@@ -1314,10 +1315,15 @@ def step_func_cat(X, args, Y, info, Ytarget, err, tols, iter, maxIter):
     print('')
     printMat(info1['stiffnessB'])
     """
-    (fAH1, fAV1, fBH1, fBV1, info1) = catenary(147.0, -25.8, 160.0, 8540000000.0, 6523.0, 
+    '''
+    # sloped case
+    (fAH1, fAV1, fBH1, fBV1, info1) = catenary(147.0, -25.8, 160.0, 854e7, 6523.0, 
             CB=0.0, alpha=-27.73, HF0=725968.57, VF0=667765.24, 
             Tol=0.0001, MaxIter=100, plots=1)
+    '''
+    # simple U case  (fAH1, fAV1, fBH1, fBV1, info1) = catenary(200, 30, 260.0, 8e9, 6500, CB=-50, nNodes=21, plots=1)
     plt.plot(info1['X'], info1['Z'] )
+    plt.plot(info1['s'], info1['X'] )
     plt.axis('equal')
 
 

moorpy/line.py

@@ -303,7 +303,7 @@ def getTimestep(self, Time):
 
 
 
-    def getLineCoords(self, Time, n=0):    # formerly UpdateLine
+    def getLineCoords(self, Time, n=0, segmentTensions=False):
         '''Gets the updated line coordinates for drawing and plotting purposes.'''
 
         if n==0: n = self.nNodes
@@ -377,7 +377,10 @@ def getLineCoords(self, Time, n=0):    # formerly UpdateLine
 
                 # handle whether or not there is tension data
                 try:  # use average to go from segment tension to node tensions <<< can skip this once MD is updated to output node tensions
-                    Te = 0.5*(np.append(self.Te[ts,0], self.Te[ts,:]) +np.append(self.Te[ts,:], self.Te[ts,-1]))
+                    if segmentTensions:
+                        Te = self.Te[ts,:]  # return tensions of segments rather than averaging to get tensions of nodes
+                    else:
+                        Te = 0.5*(np.append(self.Te[ts,0], self.Te[ts,:]) +np.append(self.Te[ts,:], self.Te[ts,-1]))
                 except: # otherwise return zeros to avoid an error (might want a warning in some cases?)
                     Te = np.zeros(self.nNodes)
 

moorpy/system.py

@@ -3065,8 +3065,11 @@ def plot(self, ax=None, bounds='default', rbound=0, color=None, **kwargs):
         draw_clumps     = kwargs.get('draw_clumps'    , False     )     # toggle to draw clump weights and float of the mooring system
         draw_anchors    = kwargs.get('draw_anchors'   , False     )     # toggle to draw the anchors of the mooring system or not  
         bathymetry      = kwargs.get("bathymetry"     , False     )     # toggle (and string) to include bathymetry or not. Can do full map based on text file, or simple squares
+        args_bath       = kwargs.get("args_bath"      , {}        )     # dictionary of optional plot_surface arguments
+        '''
         cmap_bath       = kwargs.get("cmap"           , 'ocean'   )     # matplotlib colormap specification
         alpha           = kwargs.get("opacity"        , 1.0       )     # the transparency of the bathymetry plot_surface
+        '''
         rang            = kwargs.get('rang'           , 'hold'    )     # colorbar range: if range not used, set it as a placeholder, it will get adjusted later
         cbar_bath       = kwargs.get('cbar_bath'      , False     )     # toggle to include a colorbar for a plot or not
         colortension    = kwargs.get("colortension"   , False     )     # toggle to draw the mooring lines in colors based on node tensions
@@ -3249,7 +3252,7 @@ def plot(self, ax=None, bounds='default', rbound=0, color=None, **kwargs):
             # Second method: plot a 3D surface, plot_surface
             X, Y = np.meshgrid(bathGrid_Xs, bathGrid_Ys)
 
-            bath = ax.plot_surface(X,Y,-bathGrid, cmap=cmap_bath, vmin=rang[0], vmax=rang[1], alpha=alpha)
+            bath = ax.plot_surface(X,Y,-bathGrid, vmin=rang[0], vmax=rang[1], **args_bath)
 
             if cbar_bath_size!=1.0:    # make sure the colorbar is turned on just in case it isn't when the other colorbar inputs are used
                 cbar_bath=True