R/FLSolve.R

In Fuzzy-Logix/AdapteR: Converts R syntax to SQL to provide fast analytics using in-database C++ library DB Lytix.

#' @include FLMatrix.R
NULL

#' Inverse of a Matrix.
#'
#' \code{solve} computes the inverse for FLMatrix objects.
#'
#' The wrapper overloads solve and implicitly calls FLMatrixInvUdt.
#' @seealso \code{\link[Matrix]{solve}} for corresponding R function reference
#' implementation.
#' @param x is of class FLMatrix
#' @param ... any additional arguments
#' @section Constraints:
#' Input can only be a square matrix (n x n) with maximum dimension limitations
#' of (1000 x 1000).
#' @return \code{solve} returns a FLMatrix object which is the inverse of input FLMatrix object
#' and replicates the equivalent R output.
#' @examples
#' flmatrix <- FLMatrix(getTestTableName("tblMatrixMulti"), 2,"MATRIX_ID","ROW_ID",
#'                      "COL_ID","CELL_VAL",dims= c(3,3))
#' resultFLMatrix <- solve(flmatrix)
#' 
#' ##for two arguments a,b solve(a,b) function solve ax=b equation
#' resultFLMatrix <- solve(flmatrix,flmatrix)
#' @export
solve <- function (a,b=NULL, ...){
	UseMethod("solve", a)
}
#solve.default <- base::solve
# do not define solve.default in this package as it is already defined in base::solve.default.
# It might lead to stack overflow.


#' @export
solve.FLMatrix <- function(a,b=NULL,...)
{
    ## checkSquare(object,"solve")
    ## checkSingularity(object)
  if(is.null(b))
  return(FLInv(a))
  else
  return(FLInv(a)%*%b)
}


FLInv <- function(x,...)
{

  # sqlstr<-paste0(viewSelectMatrix(x, "mtrx", withName="z"),
  #                outputSelectMatrix("FLMatrixInvUdt",
  #                                   viewName="z",
  #                                   localName="mtrx",
  #                                   includeMID=TRUE)
  #               )
    
    flm <- constructMatrixUDTSQL(pObject=x,
                                 pFuncName="FLMatrixInvUdt",
                                 pdims=rev(getDimsSlot(x)),
                                 pdimnames=rev(dimnames(x))
                                 )
    return(ensureQuerySize(pResult=flm,
                            pInput=list(x),
                            pOperator="FLInv",
                            pStoreResult=TRUE))
}