Module: Colt::Matrix2DAlgebra

Included in:
DoubleMDMatrix2D, FloatMDMatrix2D, IntMDMatrix2D, LongMDMatrix2D
Defined in:
lib/colt/matrix/algebra.rb

Instance Method Summary collapse

Instance Method Details

#mult(other_val, alpha = 1, beta = 0, transA = false, transB = false, result = nil) ⇒ Object Also known as: *

Linear algebraic matrix-matrix multiplication; C = alpha * A x B + beta*C. C = alpha*Sum(A * B) + beta*C, k=0..n-1. Matrix shapes: A(m x n), B(n x p), C(m x p). Note: Matrix shape conformance is checked after potential transpositions.



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# File 'lib/colt/matrix/algebra.rb', line 83

def mult(other_val, alpha = 1, beta = 0, transA = false, transB = false, result = nil)
  
  if (other_val.is_a? Numeric)
    MDMatrix.from_mdarray(@mdarray * other_val)
  elsif (other_val.is_a? MDMatrix)
    if (other_val.rank > 2)
      raise "Rank should be 1 or 2"
    elsif (other_val.rank == 2)      
      result = MDMatrix
        .build(@mdarray.type, [@mdarray.shape[0], 
                               other_val.mdarray.shape[1]]) if result == nil
      @colt_matrix.zMult(other_val.colt_matrix, result.colt_matrix, alpha, beta,
                         transA, transB)
    else # multiplying by a vector
      result = MDMatrix.build(@mdarray.type, [@mdarray.shape[1]]) if result == nil
      @colt_matrix.zMult(other_val.colt_matrix, result.colt_matrix, alpha, beta, transA)
    end
    
    # MDMatrix.from_colt_matrix(result)
    result
  else
    raise "Cannot multiply matrix by given value"
  end
  
end

#transpose ⇒ Object

Constructs and returns a new view which is the transposition of the given matrix A.



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# File 'lib/colt/matrix/algebra.rb', line 115

def transpose
  MDMatrix.from_mdarray(@mdarray.transpose(0, 1))
end