R/d.R

In Calculator.LR.FNs: Calculator for LR Fuzzy Numbers

d <-
function(M, N)  {
options(warn = -1) 

if ( messages(M) != 1 )  { return( messages(M) ) }
if ( messages(N) != 1 )  { return( messages(N) ) }

if ( (M[4]==1 & N[4]==0) | (M[4]==0 & N[4]==1) | (M[4]==0.5 & N[4]==0.5) ) 
  {
     if (  ( sign(M) == "Positive" )  &  ( sign(N) == "Positive" )  ) 
       {
        a1 = M[1] / N[1]
        a2 = ( ( M[1]*N[3] ) + ( N[1]*M[2] ) ) / (N[1]^2)
        a3 = ( ( M[1]*N[2] ) + ( N[1]*M[3] ) ) / (N[1]^2)
        a4 = M[4]
        print( noquote( paste0("the result of division is approximately  (core = ", a1, ", left spread = " , a2, ", right spread = " , a3, ")"
          ,  if ( a4 == 0 ) { paste0(" LR" ) }  else if ( a4 == 1 ) { paste0(" RL" ) }  else { paste0(" L" ) }  ) ) )
        return( invisible( c(a1,a2,a3,a4) ) )
       }
     else
       {
        return( noquote( paste0("A regular approximation is not defined for division since at least one of LR fuzzy numbers is not positive" ) ) )
       }
  }
else
  {
   return( noquote( paste0("Division has NOT a closed form of a LR fuzzy number" ) ) )
  }

}