R/tamaanify.grep.linequations.R

In TAM: Test Analysis Modules

## File Name: tamaanify.grep.linequations.R
## File Version: 9.07



##########################################################
# grep list of linear equations
tamaanify.grep.linequations <- function( syn2 ){
        # split syntax in matrix format
        syn3 <- strsplit( paste0(syn2), split="==", fixed=TRUE )
        syn3a <- unlist(lapply( syn3, FUN=function(ll){ ll[1] } ))
        syn3b <- unlist(lapply( syn3, FUN=function(ll){ ll[2] } ))
        L1 <- length(syn3a)
        dfr <- NULL
        for (ii in 1:L1){
            # ii <- 2
            ll1 <- unlist( strsplit( syn3b[ii], split="+", fixed=TRUE ) )
            dfr2 <- data.frame("lhsparm"=syn3a[ii], "rhsparm"=syn3b[ii],
                    "terms"=ll1 )
            dfr <- rbind( dfr, dfr2 )
                        }

        m2 <- strsplit( paste(dfr$terms)    , split="*", fixed=TRUE )
        # numerical
        dfr$fac <- as.numeric( unlist( lapply( m2, FUN=function(uu){
                    m1 <- ifelse( length(uu)==1, 1, uu[1] )
                    m1 <- gsub( "(", "", m1, fixed=TRUE )
                    m1 <- gsub( ")", "", m1, fixed=TRUE )
                    m1
                            } ) ) )
        # parameter
        dfr$parm <- unlist( lapply( m2, FUN=function(uu){
                    ifelse( length(uu)==1, uu[1], uu[2] )
                            } ) )
        rownames(dfr) <- NULL
        return(dfr)
        }
###############################################################