Merge pull request FloatingArrayDesign#156 from RyanDavies19/dev_ryan

Fixes initialization location of fixed bodies

Author: RyanDavies19

docs/drivers.rst

@@ -157,8 +157,9 @@ library. Below is an example of this on MacOS with MoorDyn compiled as a
    vector_size = 6 # 6DOF coupled object
    size = (len(time), vector_size)
 
-   x = np.zeros(size)
-   xd = np.zeros(size)
+   #specifying correct dtypes for conversion to C types
+   x = np.zeros(size, dtype = float)
+   xd = np.zeros(size, dtype = float)
 
    dylib_path = 'MoorDyn/compile/DYLIB/libmoordyn2.dylib'
    filename = path+rootname+extension

source/Body.cpp

@@ -77,7 +77,15 @@ Body::setup(int number_in,
 		bodyI = I_in;
 		bodyCdA = CdA_in;
 		bodyCa = Ca_in;
-	} else // other types of bodies have no need for these variables...
+	} else if (type == FIXED){ // fixed bodies have no need for these variables other than position...
+		bodyM = 0.0;
+		bodyV = 0.0;
+		body_r6.head<3>() = r6_in.head<3>();
+		body_r6.tail<3>() = deg2rad * r6_in.tail<3>();
+		bodyI = vec::Zero();
+		bodyCdA = vec6::Zero();
+		bodyCa = vec6::Zero();
+    } else // coupled bodies have no need for these variables...
 	{
 		bodyM = 0.0;
 		bodyV = 0.0;
@@ -375,9 +383,10 @@ Body::initiateStep(vec6 r, vec6 rd)
 		rd_ves = rd;
 		return;
 	}
-	if (type == FIXED) // if the ground body, set the BCs to stationary
+	if (type == FIXED) // if fixed body, set the BCs to stationary
 	{
-		r_ves = vec6::Zero();
+		if (bodyId == 0) r_ves = vec6::Zero(); // special ground body case
+		else r_ves = r;
 		rd_ves = vec6::Zero();
 		return;
 	}

source/MoorDyn2.cpp

@@ -205,6 +205,11 @@ moordyn::MoorDyn::Init(const double* x, const double* xd, bool skip_ic)
 	// call ground body to update all the fixed things...
 	GroundBody->initializeUnfreeBody();
 
+	// intialize fixed bodies and attached objects
+	for (auto l : FixedBodyIs){
+		BodyList[l]->initializeUnfreeBody(BodyList[l]->body_r6, vec6::Zero());
+	}
+
 	// initialize coupled objects based on passed kinematics
 	int ix = 0;
 
@@ -1732,6 +1737,7 @@ moordyn::MoorDyn::readBody(string inputText)
 		// it is fixed  (this would just be used if someone wanted
 		// to temporarly fix a body that things were attached to)
 		type = Body::FIXED;
+		FixedBodyIs.push_back(ui_size(BodyList));
 	} else if (str::isOneOf(let1, { "VESSEL", "VES", "COUPLED", "CPLD" })) {
 		// it is coupled - controlled from outside
 		type = Body::COUPLED;

source/MoorDyn2.hpp

@@ -475,6 +475,8 @@ class MoorDyn final : public io::IO
 
 	/// vector of free body indices in BodyList vector
 	vector<unsigned int> FreeBodyIs;
+	/// vector of fixed body indices in BodyList vector
+	vector<unsigned int> FixedBodyIs;
 	/// vector of coupled/fairlead body indices in BodyList vector
 	vector<unsigned int> CpldBodyIs;