matrixops.java

factorization.zip

package javax.math.factorization;

/**
 * <p>Title: Factorization Library</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author Vladimir Silva
 * @version 1.0
 */

/**
 * I am truly sorry about all this awful spagethi code
 * I got it from: Dario Alejandro Alpern (Buenos Aires - Argentina)
 * Last updated October 16th, 2003. See http://www.alpertron.com.ar/ECM.HTM
 * I am not to blame for its crappy design and implementation, but....
 * what the hell. it works!
 * I modified it though, to make it less horrible (extracted the pieces i needed)
 * If you are a brave soul,  try to port this stuff to an object oriented, well-designed
 * structure. I tried, but just gave up....
 */
public class MatrixOps {

  /* Multiply binary matrices of length m x 32 by 32 x 32 */
  /* The product matrix has size m x 32. Then add it to a m x 32 matrix. */
  static void MatrixMultAdd(int [] LeftMatr, int [] RightMatr, int [] ProdMatr) {
    int leftMatr;
    int matrLength = LeftMatr.length;
    int prodMatr;
    int row, col;
    for (row = 0; row < matrLength; row++) {
      prodMatr = ProdMatr[row];
      leftMatr = LeftMatr[row];
      col = 0;
      while (leftMatr != 0) {
        if (leftMatr < 0) {
          prodMatr ^= RightMatr[col];
        }
        leftMatr *= 2;
        col++;
      }
      ProdMatr[row] = prodMatr;
    }
  }
  /* Multiply binary matrices of length m x 32 by 32 x 32 */
  /* The product matrix has size m x 32 */
  static void MatrixMultiplication(int [] LeftMatr, int [] RightMatr, int [] ProdMatr) {
    int leftMatr;
    int matrLength = LeftMatr.length;
    int prodMatr;
    int row, col;
    for (row = 0; row < matrLength; row++) {
      prodMatr = 0;
      leftMatr = LeftMatr[row];
      col = 0;
      while (leftMatr != 0) {
        if (leftMatr < 0) {
          prodMatr ^= RightMatr[col];
        }
        leftMatr *= 2;
        col++;
      }
      ProdMatr[row] = prodMatr;
    }
  }

  /* Multiply the transpose of a binary matrix of length n x 32 by */
  /* another binary matrix of length n x 32 */
  /* The product matrix has size 32 x 32 */
  static void MatrTranspMult(int [] LeftMatr, int [] RightMatr, int [] ProdMatr) {
    int prodMatr;
    int matrLength = LeftMatr.length;
    int row, col;
    int iMask = 1;
    for (col = 31; col >= 0; col--) {
      prodMatr = 0;
      for (row = 0; row < matrLength; row++) {
        if ((LeftMatr[row] & iMask) != 0) {
          prodMatr ^= RightMatr[row];
        }
      }
      ProdMatr[col] = prodMatr;
      iMask *= 2;
    }
  }

  static void MatrixAddition(int [] leftMatr, int [] rightMatr, int [] sumMatr) {
    for (int row = leftMatr.length-1; row >= 0 ; row--) {
      sumMatr[row] = leftMatr[row] ^ rightMatr[row];
    }
  }

  static void MatrMultBySSt(int [] Matr, int diagS, int [] Prod) {
    for (int row = Matr.length-1; row >= 0 ; row--) {
      Prod[row] = diagS & Matr[row];
    }
  }

  /* Compute Bt * B * input matrix where B is the matrix that holds the */
  /* factorization relations */
  static void MultiplyAByMatrix(int [][] matrixB, int [] Matr, int [] TempMatr, int [] ProdMatr) {
    int index;
    int prodMatr;
    int row, col;
    int [] rowMatrixB;

    /* Compute TempMatr = B * Matr */
    for (row = matrixB.length-1; row >= 0; row--) {
      TempMatr[row] = 0;
    }
    for (row = matrixB.length-1; row >= 0; row--) {
      rowMatrixB = matrixB[row];
      for (index = rowMatrixB.length-1; index>=0; index--) {
        TempMatr[rowMatrixB[index]] ^= Matr[row];
      }
    }

    /* Compute ProdMatr = Bt * TempMatr */
    for (row = matrixB.length-1; row >= 0; row--) {
      prodMatr = 0;
      rowMatrixB = matrixB[row];
      for (index = rowMatrixB.length-1; index>=0; index--) {
        prodMatr ^= TempMatr[rowMatrixB[index]];
      }
      ProdMatr[row] = prodMatr;
    }
  }

  static void colexchange(int [] XmY, int [] V, int [] V1, int [] V2,
      int col1, int col2) {
    int i;
    int mask1, mask2;
    int [] matr1, matr2;

    if (col1==col2) {
      return;
    }
    mask1 = 1 << (31-(col1 & 31));
    mask2 = 1 << (31-(col2 & 31));
    matr1 = (col1 >= 32? V1: V2);
    matr2 = (col2 >= 32? V1: V2);
    for (i=V.length-1; i>=0; i--) {
      if (((matr1[i] & mask1) == 0) != ((matr2[i] & mask2) == 0)) {
        matr1[i] ^= mask1;
        matr2[i] ^= mask2;
      }
    }

    matr1 = (col1 >= 32? XmY: V);
    matr2 = (col2 >= 32? XmY: V);
    for (i=V.length-1; i>=0; i--) {
      if (((matr1[i] & mask1) == 0) != ((matr2[i] & mask2) == 0)) {
        matr1[i] ^= mask1;
        matr2[i] ^= mask2;
      }
    }
  }

  static void coladd(int [] XmY, int [] V, int [] V1, int [] V2,
      int col1, int col2)
  {
    int i;
    int mask1, mask2;
    int [] matr1, matr2;

    if (col1==col2) {
      return;
    }
    mask1 = 1 << (31-(col1 & 31));
    mask2 = 1 << (31-(col2 & 31));
    matr1 = (col1 >= 32? V1: V2);
    matr2 = (col2 >= 32? V1: V2);
    for (i=V.length-1; i>=0; i--) {
      if ((matr1[i] & mask1) != 0) {
        matr2[i] ^= mask2;
      }
    }

    matr1 = (col1 >= 32? XmY: V);
    matr2 = (col2 >= 32? XmY: V);
    for (i=V.length-1; i>=0; i--) {
      if ((matr1[i] & mask1) != 0) {
        matr2[i] ^= mask2;
      }
    }
  }


      public MatrixOps() {
      }
      public static void main(String[] args) {
	    MatrixOps matrixOps1 = new MatrixOps();
      }

}