sla.chol             package:RScaLAPACK             R Documentation

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_D_e_s_c_r_i_p_t_i_o_n:

     Compute the Choleski factorization of a real symmetric
     positive-definite square matrix using ScaLAPACK.

_U_s_a_g_e:

     sla.chol(A, NPROWS, NPCOLS, MB, RFLAG, SPAWN)

_A_r_g_u_m_e_n_t_s:

       A: A real symmetric, positive definite matrix

  NPROWS: Number of Process Rows in the Process Grid. 

  NPCOLS: Number of Process Cols in the Process Grid. 

      MB: Block Size. 

   RFLAG: Flag saying whether the Process Grid should be released after
          computation.

   SPAWN: Flag saying whether a new Process Grid should be spawned.

_D_e_t_a_i_l_s:

     If the number of processor rows and columns are both zero, one
     processor is used.  If the number of processor rows is nonzero and
     the number of processor columns is zero, then the processor rows
     is taken to be a  number of processors, and a grid is made
     accordingly.

_R_e_f_e_r_e_n_c_e_s:

     <URL: http://www.netlib.org/scalapack/>

_S_e_e _A_l_s_o:

     'sla.solve' the SCALAPACK version of the R function 'solve' 

     'sla.qr' the SCALAPACK version of the R function 'qr'

     'sla.svd' the SCALAPACK version of the R function 'La.svd' 

     'La.chol' the LAPACK function computing Choleski Factiorization in
     R.

_E_x_a_m_p_l_e_s:

     library(RScaLAPACK)
     c(4.16,0,0,0,-3.12,5.03,0,0,0.56,-0.83,0.76,0,-0.10,1.18,0.34,1.18)->x
     dim(x)=c(4,4)
     sla.chol(x)

