Class SeqBlas

java.lang.Object
cern.colt.matrix.linalg.SeqBlas
All Implemented Interfaces:
Blas
public class SeqBlas extends Object implements Blas
Sequential implementation of the Basic Linear Algebra System.
Version:
0.9, 16/04/2000

  • Field Details

    • seqBlas

      public static final Blas seqBlas
      Little trick to allow for "aliasing", that is, renaming this class. Time and again writing code like

      SeqBlas.blas.dgemm(...);

      is a bit awkward. Using the aliasing you can instead write

      Blas B = SeqBlas.blas;
      B.dgemm(...);

    • F

      private static final Functions F

  • Constructor Details

    • SeqBlas

      protected SeqBlas()
      Makes this class non instantiable, but still let's others inherit from it.

  • Method Details

    • assign

      public void assign(DoubleMatrix2D A, DoubleFunction function)
      Description copied from interface: Blas
      Assigns the result of a function to each cell; x[row,col] = function(x[row,col]).
      Specified by:
      assign in interface Blas
      Parameters:
      A - the matrix to modify.
      function - a function object taking as argument the current cell's value.
      See Also:

    • assign

      public void assign(DoubleMatrix2D A, DoubleMatrix2D B, DoubleDoubleFunction function)
      Description copied from interface: Blas
      Assigns the result of a function to each cell; x[row,col] = function(x[row,col],y[row,col]).
      Specified by:
      assign in interface Blas
      Parameters:
      A - the matrix to modify.
      B - the secondary matrix to operate on.
      function - a function object taking as first argument the current cell's value of this, and as second argument the current cell's value of y,
      See Also:

    • dasum

      public double dasum(DoubleMatrix1D x)
      Description copied from interface: Blas
      Returns the sum of absolute values; |x[0]| + |x[1]| + ... . In fact equivalent to x.aggregate(cern.jet.math.Functions.plus, cern.jet.math.Functions.abs).
      Specified by:
      dasum in interface Blas
      Parameters:
      x - the first vector.

    • daxpy

      public void daxpy(double alpha, DoubleMatrix1D x, DoubleMatrix1D y)
      Description copied from interface: Blas
      Combined vector scaling; y = y + alpha*x. In fact equivalent to y.assign(x,cern.jet.math.Functions.plusMult(alpha)).
      Specified by:
      daxpy in interface Blas
      Parameters:
      alpha - a scale factor.
      x - the first source vector.
      y - the second source vector, this is also the vector where results are stored.

    • daxpy

      public void daxpy(double alpha, DoubleMatrix2D A, DoubleMatrix2D B)
      Description copied from interface: Blas
      Combined matrix scaling; B = B + alpha*A. In fact equivalent to B.assign(A,cern.jet.math.Functions.plusMult(alpha)).
      Specified by:
      daxpy in interface Blas
      Parameters:
      alpha - a scale factor.
      A - the first source matrix.
      B - the second source matrix, this is also the matrix where results are stored.

    • dcopy

      public void dcopy(DoubleMatrix1D x, DoubleMatrix1D y)
      Description copied from interface: Blas
      Vector assignment (copying); y = x. In fact equivalent to y.assign(x).
      Specified by:
      dcopy in interface Blas
      Parameters:
      x - the source vector.
      y - the destination vector.

    • dcopy

      public void dcopy(DoubleMatrix2D A, DoubleMatrix2D B)
      Description copied from interface: Blas
      Matrix assignment (copying); B = A. In fact equivalent to B.assign(A).
      Specified by:
      dcopy in interface Blas
      Parameters:
      A - the source matrix.
      B - the destination matrix.

    • ddot

      public double ddot(DoubleMatrix1D x, DoubleMatrix1D y)
      Description copied from interface: Blas
      Returns the dot product of two vectors x and y, which is Sum(x[i]*y[i]). In fact equivalent to x.zDotProduct(y).
      Specified by:
      ddot in interface Blas
      Parameters:
      x - the first vector.
      y - the second vector.
      Returns:
      the sum of products.

    • dgemm

      public void dgemm(boolean transposeA, boolean transposeB, double alpha, DoubleMatrix2D A, DoubleMatrix2D B, double beta, DoubleMatrix2D C)
      Description copied from interface: Blas
      Generalized linear algebraic matrix-matrix multiply; C = alpha*A*B + beta*C. In fact equivalent to A.zMult(B,C,alpha,beta,transposeA,transposeB). Note: Matrix shape conformance is checked after potential transpositions.
      Specified by:
      dgemm in interface Blas
      Parameters:
      transposeA - set this flag to indicate that the multiplication shall be performed on A'.
      transposeB - set this flag to indicate that the multiplication shall be performed on B'.
      alpha - a scale factor.
      A - the first source matrix.
      B - the second source matrix.
      beta - a scale factor.
      C - the third source matrix, this is also the matrix where results are stored.

    • dgemv

      public void dgemv(boolean transposeA, double alpha, DoubleMatrix2D A, DoubleMatrix1D x, double beta, DoubleMatrix1D y)
      Description copied from interface: Blas
      Generalized linear algebraic matrix-vector multiply; y = alpha*A*x + beta*y. In fact equivalent to A.zMult(x,y,alpha,beta,transposeA). Note: Matrix shape conformance is checked after potential transpositions.
      Specified by:
      dgemv in interface Blas
      Parameters:
      transposeA - set this flag to indicate that the multiplication shall be performed on A'.
      alpha - a scale factor.
      A - the source matrix.
      x - the first source vector.
      beta - a scale factor.
      y - the second source vector, this is also the vector where results are stored.

    • dger

      public void dger(double alpha, DoubleMatrix1D x, DoubleMatrix1D y, DoubleMatrix2D A)
      Description copied from interface: Blas
      Performs a rank 1 update; A = A + alpha*x*y'. Example: 
      A = { {6,5}, {7,6} }, x = {1,2}, y = {3,4}, alpha = 1 -->
A = { {9,9}, {13,14} }
      Specified by:
      dger in interface Blas
      Parameters:
      alpha - a scalar.
      x - an m element vector.
      y - an n element vector.
      A - an m by n matrix.

    • dnrm2

      public double dnrm2(DoubleMatrix1D x)
      Description copied from interface: Blas
      Return the 2-norm; sqrt(x[0]^2 + x[1]^2 + ...). In fact equivalent to Math.sqrt(Algebra.DEFAULT.norm2(x)).
      Specified by:
      dnrm2 in interface Blas
      Parameters:
      x - the vector.

    • drot

      public void drot(DoubleMatrix1D x, DoubleMatrix1D y, double c, double s)
      Description copied from interface: Blas
      Applies a givens plane rotation to (x,y); x = c*x + s*y; y = c*y - s*x.
      Specified by:
      drot in interface Blas
      Parameters:
      x - the first vector.
      y - the second vector.
      c - the cosine of the angle of rotation.
      s - the sine of the angle of rotation.

    • drotg

      public void drotg(double a, double b, double[] rotvec)
      Description copied from interface: Blas
      Constructs a Givens plane rotation for (a,b). Taken from the LINPACK translation from FORTRAN to Java, interface slightly modified. In the LINPACK listing DROTG is attributed to Jack Dongarra
      Specified by:
      drotg in interface Blas
      Parameters:
      a - rotational elimination parameter a.
      b - rotational elimination parameter b.
      rotvec - [] Must be at least of length 4. On output contains the values {a,b,c,s}.

    • dscal

      public void dscal(double alpha, DoubleMatrix1D x)
      Description copied from interface: Blas
      Vector scaling; x = alpha*x. In fact equivalent to x.assign(cern.jet.math.Functions.mult(alpha)).
      Specified by:
      dscal in interface Blas
      Parameters:
      alpha - a scale factor.
      x - the first vector.

    • dscal

      public void dscal(double alpha, DoubleMatrix2D A)
      Description copied from interface: Blas
      Matrix scaling; A = alpha*A. In fact equivalent to A.assign(cern.jet.math.Functions.mult(alpha)).
      Specified by:
      dscal in interface Blas
      Parameters:
      alpha - a scale factor.
      A - the matrix.

    • dswap

      public void dswap(DoubleMatrix1D x, DoubleMatrix1D y)
      Description copied from interface: Blas
      Swaps the elements of two vectors; y invalid input: '<'==> x. In fact equivalent to y.swap(x).
      Specified by:
      dswap in interface Blas
      Parameters:
      x - the first vector.
      y - the second vector.

    • dswap

      public void dswap(DoubleMatrix2D A, DoubleMatrix2D B)
      Description copied from interface: Blas
      Swaps the elements of two matrices; B invalid input: '<'==> A.
      Specified by:
      dswap in interface Blas

    • dsymv

      public void dsymv(boolean isUpperTriangular, double alpha, DoubleMatrix2D A, DoubleMatrix1D x, double beta, DoubleMatrix1D y)
      Description copied from interface: Blas
      Symmetric matrix-vector multiplication; y = alpha*A*x + beta*y. Where alpha and beta are scalars, x and y are n element vectors and A is an n by n symmetric matrix. A can be in upper or lower triangular format.
      Specified by:
      dsymv in interface Blas
      Parameters:
      isUpperTriangular - is A upper triangular or lower triangular part to be used?
      alpha - scaling factor.
      A - the source matrix.
      x - the first source vector.
      beta - scaling factor.
      y - the second vector holding source and destination.

    • dtrmv

      public void dtrmv(boolean isUpperTriangular, boolean transposeA, boolean isUnitTriangular, DoubleMatrix2D A, DoubleMatrix1D x)
      Description copied from interface: Blas
      Triangular matrix-vector multiplication; x = A*x or x = A'*x. Where x is an n element vector and A is an n by n unit, or non-unit, upper or lower triangular matrix.
      Specified by:
      dtrmv in interface Blas
      Parameters:
      isUpperTriangular - is A upper triangular or lower triangular?
      transposeA - set this flag to indicate that the multiplication shall be performed on A'.
      isUnitTriangular - true --> A is assumed to be unit triangular; false --> A is not assumed to be unit triangular
      A - the source matrix.
      x - the vector holding source and destination.

    • idamax

      public int idamax(DoubleMatrix1D x)
      Description copied from interface: Blas
      Returns the index of largest absolute value; i such that |x[i]| == max(|x[0]|,|x[1]|,...)..
      Specified by:
      idamax in interface Blas
      Parameters:
      x - the vector to search through.
      Returns:
      the index of largest absolute value (-1 if x is empty).

    • sign

      private double sign(double a, double b)
      Implements the FORTRAN sign (not sin) function. See the code for details.
      Parameters:
      a - a
      b - b