/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOUSE. See the GNU
 * General Public License for more details.
 *
 * You should have recieved a copy of the GNU General Public License
 * along with this program; if not write to the Free Software
 * Foundation, inc., 59 Temple Place, Suite 330, Boston MA 02111-1307
 * USA
 */

package run.elements;

import run.*;

import java.util.Vector;
import java.text.ParseException;

import jp.lang.DistributedRuntime;


/**
 * Insert the type's description here. Creation date: (08/09/01 %T)
 *
 * @author: Jonas Forssell
 */
public class Rod_2 extends Element {
    private static int DISABLED = 0;
    private static int BASIC = 1;
    private double cross_section_area;
    private Material material;
    private Jama.Matrix local_coordinate_system;
    private double diameter;
    private double initial_length;
    private Jama.Matrix inertia;
    private Jama.Matrix strain;
    private Jama.Matrix stress;
    private Jama.Matrix force;
    private Jama.Matrix dstrain;
    private double initial_cross_section_area;
    private double factor, friction;
    private boolean D_is_set;
    private boolean Nodes_are_set;
    private boolean Material_is_set;
    private boolean Factor_is_set, Friction_is_set;
    private Contact_Line internal_contact_element;
    private int Contact;

    /**
     * This is the Rod element. A simple element without moment capacity.
     * However, it is a good template to look at in order to understand the
     * buildup of an element.
     */
    public Rod_2() {
        super();
        type = new String("ROD_2");

        inertia = new Jama.Matrix(3, 3);
        force = new Jama.Matrix(3, 1);
        stress = new Jama.Matrix(6, 1);
        strain = new Jama.Matrix(6, 1);
        dstrain = new Jama.Matrix(6, 1);
        local_coordinate_system = new Jama.Matrix(3, 3);
        processed = false;
        node = new Node[2];
        
        // Enable contact by default
        Contact = BASIC;
    }

    /**
     * This metod calculates the elements contribution regarding mass and
     * rotational interta to the nodes. Since this program uses lumped mass,
     * all the mass are concentrated to the nodes, and so are the Inertia of
     * rotation as well. The mass is usually quite simple to calculate. In
     * this example it is half of the rod in each node. For a shell element it
     * could be slighty more trickier. The difficult part comes when the
     * rotational inertia is to be calculated since this is needs to be
     * calculated in three dimensions and then transformed to the global xyz
     * coordinate system before adding to the node. Some simplifications has been
     * made though as seen later.
     * Creation date: (10/5/2001 3:32:57 PM)
     */
    public void assembleMassMatrix()
        throws Error
    {
        double mass;

        // Calculate element mass distribution
        initial_cross_section_area = (Math.PI * diameter * diameter) / 4;
        cross_section_area = initial_cross_section_area;

        // Check area
        if (cross_section_area <= 0) {
            throw new Error(
                "Error in rod element " + number +
                ", Cross section area is zero or negative"
            );
        }

        //
        initial_length = java.lang.Math.sqrt(
                ((node[0].getX_pos() - node[1].getX_pos()) * (node[0].getX_pos() -
                node[1].getX_pos())) +
                ((node[0].getY_pos() - node[1].getY_pos()) * (node[0].getY_pos() -
                node[1].getY_pos())) +
                ((node[0].getZ_pos() - node[1].getZ_pos()) * (node[0].getZ_pos() -
                node[1].getZ_pos()))
            );
        mass = material.getDensity() * cross_section_area * initial_length;

        // Check mass
        if (mass <= 0) {
            throw new Error(
                "Error in rod element " + number +
                ". Element mass is zero or negative.\nElement length: " +
                initial_length + "   Material density: " +
                material.getDensity()
            );
        }

        // Distribute the mass to the connected nodes. Half mass on each node.
        node[0].addMass(mass / 2.0);
        node[1].addMass(mass / 2.0);

        /* Now, calculate the element local inertia
         * For a rod, there are two different inertias;
         * 1. Rotational inertia around the center longitudinal axis (m*d2/8)
         * 2. Rotational inertia around the middle point of the bar. Any centripetal axis (m*l2/12).
         *
         * It has been determined that inertia applied to nodes has limited
         * influence and that some simplifications can be made.
         * In this case, the largest inertia will be kept and applied
         * to all directions. Couplings will be set to zero. This
         * simplification is also used in the other elements.
         * 2005-09-17 version 0.6.3 - JF  */

        inertia.set(0,0,Math.max((mass * diameter * diameter) / 8, (mass * initial_length * initial_length) / 12));
        inertia.set(1, 1, inertia.get(0,0));
        inertia.set(2, 2, inertia.get(0,0));
        inertia.set(1, 0, 0);
        inertia.set(2, 0, 0);
        inertia.set(0, 1, 0);
        inertia.set(0, 2, 0);
        inertia.set(2, 1, 0);
        inertia.set(1, 2, 0);

        
        node[0].addInertia(inertia);
        node[1].addInertia(inertia);

        //
        if (Contact == BASIC) {
            internal_contact_element.assembleMassMatrix();
        }
    }

    /**
     * This is a biggie. The contact forces are calculated here. This is done
     * in the following way: Let this element check it's segment(s) against
     * any neighbouring nodes.     calculate distance from segment to node if
     * distance &lt; tolerance then  reactionforce = f(tolerance) add
     * reactionforce to node & element nodes             Continue this check
     * until all the nodes within the contact tolerance has been checked.
     * Creation date: (2001-10-26 01.06.35)
     */
    public void calculateContactForces() {
        // Use the internal contact element to calculate the contact forces.
        if (Contact == BASIC) {
            internal_contact_element.calculateContactForces();
        }
    }

    /**
     * Here, the contribution from gravity and external forces on ELEMENTS are
     * contributed for. Creation date: (2001-10-26 01.01.21)
     */
    public void calculateExternalForces(double currtime) {
        // Calculate gravity force here.
        // convert and add to node.
        // Calculate element loads here
        // convert and add to node.
        //
        if (Contact == BASIC) {
            internal_contact_element.calculateExternalForces(currtime);
        }
    }

    /**
     * This calculates and adds the element internal forces to the nodes. Note,
     * by definition, the internal forces are subtracted from the external
     * loads Thus, the "addition" is negative. Creation date: (2001-10-23
     * 14.03.06)
     *
     * @exception java.lang.Error The exception description.
     */
    public void calculateNodalForces(int integration_point)
        throws java.lang.Error
    {
        Jama.Matrix global_force;

        // Forces
        force.set(0, 0, stress.get(0, 0) * cross_section_area);
        force.set(1, 0, 0);
        force.set(2, 0, 0);

        // Transform to global coordinates
        global_force = local_coordinate_system.transpose().times(force);

        // Add this force contribution to the node
        node[0].addInternalForce(global_force.times(1));
        node[1].addInternalForce(global_force.times(-1));
    }

    /**
     * This method calculates the true strain of the rod. Creation date:
     * (2001-10-23 00.52.18) Jonas Forssell
     *
     * @exception java.lang.Error The exception description.
     */
    public void calculateStrain(double timestep, int integration_point)
        throws java.lang.Error
    {
        double xpos1;
        double ypos1;
        double zpos1;
        double xpos2;
        double ypos2;
        double zpos2;
        double new_length;

        //
        xpos1 = node[0].getX_pos();
        ypos1 = node[0].getY_pos();
        zpos1 = node[0].getZ_pos();

        //
        xpos2 = node[1].getX_pos();
        ypos2 = node[1].getY_pos();
        zpos2 = node[1].getZ_pos();

        //
        new_length = java.lang.Math.sqrt(
                ((xpos2 - xpos1) * (xpos2 - xpos1)) +
                ((ypos2 - ypos1) * (ypos2 - ypos1)) +
                ((zpos2 - zpos1) * (zpos2 - zpos1))
            );

        // True strain is calculated as strain = ln(1+(l-l0)/l0)
        dstrain.set(
            0, 0,
            Math.log(1 + ((new_length - initial_length) / initial_length)) -
            strain.get(0, 0)
        );

        // Calculate also the new cross section area (assuming incompressible material)
        cross_section_area = (initial_cross_section_area * initial_length) / new_length;
    }

    /**
     * This method calculates the stress of the element. In most cases, this is
     * a matrix. Here, it is only one value, which makes things easier.
     * Creation date: (2001-10-23 13.51.34)
     *
     * @exception java.lang.Error The exception description.
     */
    public void calculateStress(int integration_point, double timestep)
        throws java.lang.Error
    {
        // Now let the material law do its job and update them
        material.calculateStressOneDimensional(
            strain, dstrain, stress, timestep
        );
    }

    /**
     * This method calculates the timestep for the element and returns the
     * smallest of the current timestep and the element timestep since it is
     * the smallest element that determines the stability of the solution.
     * Creation date: (10/12/01 %T)
     *
     * @param current_timestep double
     *
     * @return double
     */
    public double checkTimestep(double current_timestep) {
        double timestep;
        double critical_length;
        double xpos1;
        double ypos1;
        double zpos1;
        double xpos2;
        double ypos2;
        double zpos2;

        //
        xpos1 = node[0].getX_pos();
        ypos1 = node[0].getY_pos();
        zpos1 = node[0].getZ_pos();

        //
        xpos2 = node[1].getX_pos();
        ypos2 = node[1].getY_pos();
        zpos2 = node[1].getZ_pos();

        //
        critical_length = java.lang.Math.sqrt(
                ((xpos2 - xpos1) * (xpos2 - xpos1)) +
                ((ypos2 - ypos1) * (ypos2 - ypos1)) +
                ((zpos2 - zpos1) * (zpos2 - zpos1))
            );

        /* Calculate critical timestep using the Courant condition
         *  timestep <= L/c
         *  L= element length
         *  c= aucustic wave speed = sqrt(E/density)
         */
        timestep = critical_length / material.wavespeedOneDimensional(0.0, 0.0);

        return Math.min(0.9 * timestep, current_timestep);
    }

    /**
     * Insert the method's description here. Creation date: (2001-10-22
     * 23.50.50)
     *
     * @return double
     */
    private double getI1() {
        return inertia.get(0, 0);
    }

    /**
     * Insert the method's description here. Creation date: (2001-10-22
     * 23.50.59)
     *
     * @return double
     */
    private double getI2() {
        return inertia.get(1, 1);
    }

    /**
     * Insert the method's description here. Creation date: (2001-10-22
     * 23.50.50)
     *
     * @return double
     */
    private double getI3() {
        return inertia.get(2, 2);
    }

    /**
     * This element only has one integration point (gauss point) Creation date:
     * (26/12/01 %T)
     *
     * @return int
     */
    public int getNumberOfIntegrationPoints() {
        return 1;
    }

    /**
     * Returns the local force of the rod.
     *
     * @return double
     */
    public double getForce() {
        return force.get(0, 0);
    }

    /**
     * Insert the method's description here. Creation date: (14/09/01 %T)
     *
     * @param param1 java.lang.String
     * @param param2 java.lang.String
     * @param param4 double
     * @param lineno int
     * @param nodelist java.util.Vector
     * @param materiallist java.util.Vector
     *
     * @exception java.text.ParseException The exception description.
     */
    public void parse_Fembic(
        Token[] param, int lineno, RplVector nodelist, RplVector materiallist,
        RplVector loadlist
    )
        throws java.text.ParseException
    {
        int nodenumber;
        int i = 0;
        Token[] contact_input;

        while (i < param.length) {
            // The nodes of the element are defined
            if (
                param[i].getw().toUpperCase().equals("NODES") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // Assume now that the nodes are delivered in param3, with the format
                // [nodenr,nodenr]
                if (
                    ! param[i + 2].getw().toUpperCase().startsWith("[") ||
                    ! param[i + 2].getw().toUpperCase().endsWith("]")
                ) {
                    throw new java.text.ParseException(
                        "Error, node number definition should be [nodenr,nodenr]",
                        lineno
                    );
                }

                // Ok, now find the numbers
                try {
                    nodenumber = super.getNodeNumber(1, param[i + 2].getw());

                    // We now have the node number, but want to have the handle to the node object.
                    node[0] = super.findNode(nodenumber, nodelist);

                    // And repeat for second node
                    nodenumber = super.getNodeNumber(2, param[i + 2].getw());
                    node[1] = super.findNode(nodenumber, nodelist);
                    i += 3;
                    Nodes_are_set = true;
                } catch (IllegalArgumentException e) {
                    throw new java.text.ParseException(
                        "Error in Rod_2 element\n" + e.getMessage() +
                        "in line ", lineno
                    );
                }
            } else
            // The material of the element is defined
            if (
                param[i].getw().toUpperCase().equals("MATERIAL") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // Assume now that the material name is delivered in param3
                try {
                    // We want the handle to the material object.
                    material = super.findMaterial(
                            param[i + 2].getw().toUpperCase(), materiallist
                        );
                    i += 3;
                    Material_is_set = true;
                } catch (IllegalArgumentException e) {
                    throw new java.text.ParseException(e.getMessage(), lineno);
                }
            } else
            // The cross section area of the element is defined
            if (
                param[i].getw().toUpperCase().equals("D") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // The value of the cross section area is in param4. Set this in the element
                diameter = param[i + 2].getn();
                i += 3;
                D_is_set = true;
            } else
            // The factor for the internal contact element is defined
            if (
                param[i].getw().toUpperCase().equals("FACTOR") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // The value of the element thickness is in param3. Set this in the element
                factor = param[i + 2].getn();
                i += 3;
                Factor_is_set = true;
            } else
                // The friction for the internal contact element is defined
            if (
                param[i].getw().toUpperCase().equals("FRICTION") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // The value of the element friction is in param3. Set this in the element
                friction = param[i + 2].getn();
                i += 3;
                Friction_is_set = true;
            } else
            // The contact element of the shell is specified
            if (
                param[i].getw().toUpperCase().equals("CONTACT") &&
                param[i + 1].getw().toUpperCase().equals("=")
            ) {
                // The value of the element thickness is in param3. Set this in the element
                if (param[i + 2].getw().toUpperCase().equals("OFF")) {
                    Contact = DISABLED;
                } else {
                    throw new java.text.ParseException(
                        "Unrecognized contact parameter", lineno
                    );
                }

                i += 3;
            } else {
                // Neither material or nodes are defined. Then the parameter is wrong.
                throw new java.text.ParseException(
                    "Unknown Rod element parameter ", lineno
                );
            }
        }

        // Make a local instance of a contact element to handle the contacts
        if (Contact == BASIC) {
            internal_contact_element = new Contact_Line();
            internal_contact_element.setNumber(-1);

			i = 6;

            // Make the input for the contact element
            if (Factor_is_set) i += 3;
            if (Friction_is_set) i += 3;

            contact_input = new Token[i];

            contact_input[0] = new Token(new String("nodes"));
            contact_input[1] = new Token(new String("="));
            contact_input[2] = new Token(
                    new String(
                        "[" + node[0].getNumber() + "," + node[1].getNumber() +
                        "]"
                    )
                );
            contact_input[3] = new Token(new String("D"));
            contact_input[4] = new Token(new String("="));
            contact_input[5] = new Token(diameter);

			i = 6;

            if (Factor_is_set) {
                contact_input[i] = new Token(new String("factor"));
                contact_input[i+1] = new Token(new String("="));
                contact_input[i+2] = new Token(factor);
                i+=3;
            }

            if (Friction_is_set) {
                contact_input[i] = new Token(new String("friction"));
                contact_input[i+1] = new Token(new String("="));
                contact_input[i+2] = new Token(friction);
                i+=3;
            }

            // Now, set the input for the contact element also
            internal_contact_element.parse_Fembic(
                contact_input, lineno, nodelist, materiallist, loadlist
            );
        }
    }

	/**
 * Insert the method's description here. Creation date: (25/12/01 %T)
 */
    public void parse_Nastran(
        Token[] param, Token[] param2, int lineno, RplVector nodelist, RplVector materiallist,
        RplVector loadlist
    )
        throws java.text.ParseException
    {
        int i = 0;
        int index;
        Constraint temp_constraint;
        Load temp_load;

		Contact = DISABLED;

        if (param[1].is_a_number()) {
			number = (int)param[1].getn();
        } 
        else 
        throw new java.text.ParseException(
                  "Illegal identification number of CBAR: " + param[1].getn(),lineno
                        );
/*
        Skip param 2 beacuse this is the reference for the pbar id
*/

        	if (param[3].is_a_number() && param[4].is_a_number()) {
                try {
                     node[0] = super.findNode((int)param[3].getn(), nodelist);
                     node[1] = super.findNode((int)param[4].getn(), nodelist);
                    }
                 catch (IllegalArgumentException e) {
                    throw new ParseException(e.getMessage(), lineno);
                }
	         } 
    	    else 
        	throw new java.text.ParseException(
                  "Illegal node number for CTRIA3: " + number,lineno
                        );

        Nodes_are_set = true;

// Now, read the property card

// Read the material number (= name)
        if (param2[2].is_a_number()) {
                try {
                    // We want the handle to the material object.
                    material = super.findMaterial(new String("Mat_" + (int)param2[2].getn())
                            , materiallist );
                    Material_is_set = true;
                } catch (IllegalArgumentException e) {
                    throw new java.text.ParseException(
                        "Material not found for PBAR: " + param2[2].getn() + "\n" + e.getMessage(), lineno
                    );
                }

        } 
        else 
        throw new java.text.ParseException(
                  "Illegal material number in PBAR : " + param2[2].getn(),lineno
                        );

        if (param2[3].is_a_number()) {
			diameter = Math.sqrt(4*param2[3].getn()/Math.PI);
			D_is_set = true;

        } 
        else 
        throw new java.text.ParseException(
                  "Illegal area defined in PBAR : " + param2[3].getn(),lineno
                        );

    }

	/**
 * Insert the method's description here. Creation date: (25/12/01 %T)
 */
    public void parse_Gmsh(
        Token[] param, int lineno, RplVector nodelist, RplVector materiallist,
        RplVector loadlist
    )
        throws java.text.ParseException
    {
    	int i,j;
		Token[] contact_input;
    	
        try {

       		number = (int)param[0].getn();
        	
           	node[0] = super.findNode( (int)param[5].getn(), nodelist );
           	node[1] = super.findNode( (int)param[6].getn(), nodelist );
            Nodes_are_set = true;

			diameter = param[2].getn() % 1000;
			diameter /= 10;			
			D_is_set = true;

			j = (int)param[2].getn() / 1000;
			j %= 100;
            material = super.findMaterial(
            				new String("MAT_"+j), materiallist
                        );
            Material_is_set = true;
			

        // Make a local instance of a contact element to handle the contacts
        if (Contact == BASIC) {
            internal_contact_element = new Contact_Line();
            internal_contact_element.setNumber(-1);

			i = 6;

            // Make the input for the contact element
            if (Factor_is_set) i += 3;
            if (Friction_is_set) i += 3;

            contact_input = new Token[i];

            contact_input[0] = new Token(new String("nodes"));
            contact_input[1] = new Token(new String("="));
            contact_input[2] = new Token(
                    new String(
                        "[" + node[0].getNumber() + "," + node[1].getNumber() +
                        "]"
                    )
                );
            contact_input[3] = new Token(new String("D"));
            contact_input[4] = new Token(new String("="));
            contact_input[5] = new Token(diameter);

			i = 6;

            if (Factor_is_set) {
                contact_input[i] = new Token(new String("factor"));
                contact_input[i+1] = new Token(new String("="));
                contact_input[i+2] = new Token(factor);
                i+=3;
            }

            if (Friction_is_set) {
                contact_input[i] = new Token(new String("friction"));
                contact_input[i+1] = new Token(new String("="));
                contact_input[i+2] = new Token(friction);
                i+=3;
            }

            // Now, set the input for the contact element also
            internal_contact_element.parse_Fembic(
                contact_input, lineno, nodelist, materiallist, loadlist
            );
        }



            } catch (IllegalArgumentException e) {
                    throw new java.text.ParseException(
                        e.getMessage() + " in line ", lineno
					);
        }

    	
    }


    public void checkIndata()
        throws Error
    {
        // Check that all the required parameters have been parsed
        if (! D_is_set) {
            throw new Error("No Diameter defined for Rod element nr" + number);
        }

        if (! Nodes_are_set) {
            throw new Error("No nodes defined for Rod element nr" + number);
        }

        if (! Material_is_set) {
            throw new Error("No Material defined for Rod element nr" + number);
        }

        //
        if (Contact == BASIC) {
            internal_contact_element.checkIndata();
        }
    }

    public void checkIfFailed() {
        if (! material.failureStrainIsSet() && ! material.failureStressIsSet()) {
            failed = false;
            return;
        }

        if (material.failureStressIsSet()) {
            if (stress.get(0, 0) > material.getFailureStress()) {
                failed = true;
                return;
            }
        }

        if (material.failureStrainIsSet()) {
            if (strain.get(0, 0) > material.getFailureStrain()) {
                failed = true;
                return;
            }
        }

        failed = false;
    }

    /**
     * This method is used to create the lines needed in the result file. The
     * method returns a string which is printed directly. However, due to the
     * fact that the line may be different depending on what is requested to
     * be printed and that the number of methods should be kept down, the
     * first parameter here is a control parameter. This parameter describes
     * what should be printed. The second parameter is a required input when
     * gauss point results are to be printed. Creation date: (09/12/01 %T)
     *
     * @param ctrl int
     * @param gpn int
     *
     * @return java.lang.String
     */
    public String print_Gid(int ctrl, int gpn) {
        String out;

        switch (ctrl) {
        case MESH_HEADER:

            /* Print the header for the mesh.
             * In this case, the type of element is Linear and it a Rod uses 2 nodes
             */
            out = new String(
                    "MESH \"MeshType" + type +
                    "\" Dimension 3 ElemType Linear Nnode 2\n"
                );

            return out;

        case MESH:

            /* Print the element number and connected nodes */
            out = new String(
                    number + "\t" + node[0].getNumber() + "\t" +
                    node[1].getNumber() + "\n"
                );

            return out;

        case RESULT_HEADER:

            /* Print the header of the result file, for the block of Rod elements */
            out = new String(
                    "GaussPoints \"Type" + type +
                    "\" ElemType Linear \"MeshType" + type + "\"\n"
                );
            out += "Number Of Gauss Points: 1\n";
            out += "Nodes Not Included\n";
            out += "Natural Coordinates: Internal\n";
            out += "End GaussPoints\n";

            return out;

        case RESULT_SUB_HEADER:

            /* Print the subheader for the resultfile to initate each block of data from this element type */
            out = new String(" 1 2 0 \"Type" + type + "\"\n");

            return out;

        case RESULT_STRESS_LOCAL:

            /* Print the Gauss stresses for this element, remembering the previous line index */
            out = new String(number + " ");
            out += (stress.get(0, 0) + "\n");

            return out;

        case RESULT_STRAIN_LOCAL:

            /* Print the Gauss stresses for this element, remembering the previous line index */
            out = new String(number + " ");
            out += (strain.get(0, 0) + "\n");

            return out;

        default:
            return new String("");
        }
    }


    /**
     * This method is used to create the lines needed in the result file. The
     * method returns a string which is printed directly. However, due to the
     * fact that the line may be different depending on what is requested to
     * be printed and that the number of methods should be kept down, the
     * first parameter here is a control parameter. This parameter describes
     * what should be printed. The second parameter is a required input when
     * gauss point results are to be printed. Creation date: (09/12/01 %T)
     *
     * @param ctrl The control number to say if a header of result file is to
     *        be printed.
     * @param gpn The gauss point number.
     *
     * @return java.lang.String
     */
    public String print_Fembic(int ctrl, int gpn) {
        String out;

        switch (ctrl) {

        case MESH:

            /* Print the element number and connected nodes */
            out = new String(
                    number + "\t nodes = [" + node[0].getNumber() + "," +
                    node[1].getNumber() + "]\t"
                    + "D = " + diameter + "\t"
                    + "material = " + material.getName() + "\t"
                );
               

            if (Factor_is_set) 
            	out += " factor = " + factor;

            if (Friction_is_set) 
            	out += " friction = " + friction;

            if (Contact == DISABLED) 
            	out += " contact = OFF";


			out += "\n";

            return out;


        default:
            return new String("");
        }
    }


    /**
     * Insert the method's description here. Creation date: (27/09/01 %T)
     */
    public void setInitialConditions()
        throws Error
    {
        /* Make a local copy of the material object and keep it inside the element.
         * The reason for this is twofold.
         * 1. The material law is now tied to the element and will remember the element properties and history
         * 2. Since the material is cloned now, after Initialize, all the parameters are defined in the material object and are
         * now automatically transferred to the local copy.
         */
        try {
            material = (Material) material.copy();
        } catch (CloneNotSupportedException e) {
            System.err.println("Object cannot clone");
        }

        // Now call any necessary initialisations in the law.
        material.setInitialConditions();

        // Initalize the contact element also
        if (Contact == BASIC) {
            internal_contact_element.setInitialConditions();
        }
    }

    /**
     * This method sets up the local coordinate system for the element.     The
     * local x-axis will run from node 1 to node 2. The local y-axis will be
     * in the plane given by the local x-axis     and the point formed by the
     * coordinates of node 1, but with and offset of 1 mm in x and y
     * direction.     The local z-axis will be orthogonal to the same plane.
     * In the case of a rod, the directions of the y-and z-axis are really not
     * that important since it is symmetric.     The local system is unified
     * in length. The forces and inertias can now be expresses relative to
     * this     system and then transformed Creation date: (19/11/01 %T)
     */
    public void updateLocalCoordinateSystem() {
        this.calculateLocalBaseVectors(
            0, 0, 0, node[1].getX_pos() - node[0].getX_pos(),
            node[1].getY_pos() - node[0].getY_pos(),
            node[1].getZ_pos() - node[0].getZ_pos(),
            node[1].getZ_pos() - node[0].getZ_pos(),
            node[0].getX_pos() - node[1].getX_pos(),
            node[1].getY_pos() - node[0].getY_pos(), local_coordinate_system
        );

        // Update local coordiante system on the contact element
        if (Contact == BASIC) {
            internal_contact_element.updateLocalCoordinateSystem();
        }
    }

    /**
     * Is used to deactivate the element when fractured.
     */
    public void deActivate() {
        super.deActivate();
        if (internal_contact_element != null) internal_contact_element.deActivate();
    }

}

