Exemple #1
0
        /// <summary>
        /// Performs ICP Alignment using LIBICP 1.4.7.
        /// Checks if the proteins fit the minimum requirements of the alignment.
        /// Throws if it does not, or if there are less than two proteins loaded.
        /// Extract the alpha carbon matrix from the proteins. Sets up the translation and rotation matrices.
        /// Fits the two matrices using ICP. The rotation matrix is applied to a full atom matrix of Protein2.
        /// Protein2 is then translated. Calls RMSD() to calculate the RMSD between the two proteins.
        /// </summary>
        /// <returns>RMSD value between the two proteins.</returns>
        public double ICPAlignment()
        {
            if (Protein1.Count == 0)
            {
                throw (new Exception("Alignment Error: Protein 1 not found."));
            }
            if (Protein2.Count == 0)
            {
                throw (new Exception("Alignment Error: Protein 2 not found."));
            }
            //LIBICP doesnt work with less than 5 points
            if (Protein1.CACount < 5 || Protein2.CACount < 5)
            {
                throw (new Exception("Alignment Error: Not enough atoms for alignment."));
            }
            //aligns by CA backbone
            double[,] prot1Mat = m_prot1.CAMatrix();
            double[,] prot2Mat = m_prot2.CAMatrix();
            icp_net.ManagedICP align = new icp_net.ManagedICP(prot1Mat, Protein1.CACount, 3);

            //set up return Rotation matrix
            double[,] RMat = new double[3, 3];
            RMat[0, 0]     = 1.0;
            RMat[1, 1]     = 1.0;
            RMat[2, 2]     = 1.0;
            //set up return Translation matrix
            double[] TMat = new double[3];

            //last parameter is inlier distance, if <= 0, uses all points
            align.fit(prot2Mat, Protein2.CACount, RMat, TMat, -1);

            //get full atom matrix to transform
            // LIBICP actually takes in a n x 3 matrix, but we need a 3 x n matrix for the math, so ToMatrix() gives a full atom matrix in that orientation
            double[,] prot2FullMat = m_prot2.ToMatrix();
            //create objects of Matrix type to perfrom matrix multiplication
            Matrix <double> prot2MatObj = DenseMatrix.OfArray(prot2FullMat);
            Matrix <double> RMatObj     = DenseMatrix.OfArray(RMat);

            /*To get the Final dataset B, given dataset A
             * B = RMat * A + TMat;
             * Thus Rotation is applied first
             */
            prot2MatObj = RMatObj * prot2MatObj;
            //sets the protein coordinates to the matrix
            m_prot2.FromMatrix(prot2MatObj);
            //translate
            m_prot2.Translate(TMat[0], TMat[1], TMat[2]);
            return(RMSD());
        }
Exemple #2
0
        /// <summary>
        /// Performs ICP Alignment using LIBICP 1.4.7.
        /// Checks if the proteins fit the minimum requirements of the alignment. 
        /// Throws if it does not, or if there are less than two proteins loaded.
        /// Extract the alpha carbon matrix from the proteins. Sets up the translation and rotation matrices.
        /// Fits the two matrices using ICP. The rotation matrix is applied to a full atom matrix of Protein2.
        /// Protein2 is then translated. Calls RMSD() to calculate the RMSD between the two proteins.
        /// </summary>
        /// <returns>RMSD value between the two proteins.</returns>
        public double ICPAlignment()
        {
            if (Protein1.Count == 0)
            {
                throw (new Exception("Alignment Error: Protein 1 not found."));
            }
            if (Protein2.Count == 0)
            {
                throw (new Exception("Alignment Error: Protein 2 not found."));
            }
            //LIBICP doesnt work with less than 5 points
            if (Protein1.CACount < 5 || Protein2.CACount < 5)
            {
                throw (new Exception("Alignment Error: Not enough atoms for alignment."));
            }
            //aligns by CA backbone
            double[,] prot1Mat = m_prot1.CAMatrix();
            double[,] prot2Mat = m_prot2.CAMatrix();
            icp_net.ManagedICP align = new icp_net.ManagedICP(prot1Mat, Protein1.CACount, 3);

            //set up return Rotation matrix
            double[,] RMat = new double[3, 3];
            RMat[0, 0] = 1.0;
            RMat[1, 1] = 1.0;
            RMat[2, 2] = 1.0;
            //set up return Translation matrix
            double[] TMat = new double[3];

            //last parameter is inlier distance, if <= 0, uses all points
            align.fit(prot2Mat, Protein2.CACount, RMat, TMat, -1);

            //get full atom matrix to transform
            // LIBICP actually takes in a n x 3 matrix, but we need a 3 x n matrix for the math, so ToMatrix() gives a full atom matrix in that orientation
            double[,] prot2FullMat = m_prot2.ToMatrix();
            //create objects of Matrix type to perfrom matrix multiplication
            Matrix<double> prot2MatObj = DenseMatrix.OfArray(prot2FullMat);
            Matrix<double> RMatObj = DenseMatrix.OfArray(RMat);
            /*To get the Final dataset B, given dataset A
             * B = RMat * A + TMat;
             * Thus Rotation is applied first
             */
            prot2MatObj = RMatObj * prot2MatObj;
            //sets the protein coordinates to the matrix
            m_prot2.FromMatrix(prot2MatObj);
            //translate
            m_prot2.Translate(TMat[0], TMat[1], TMat[2]);
            return RMSD();
        }