spsort {crank} | R Documentation |
Sort the elements in a vector according to a set of precedence rules.
spsort(x,L=NULL)
x |
A matrix or data frame with at least two columns. The first two columns are interpreted as precedence pairs, meaning that the element in column 1 should appear before the one in column 2. |
L |
The vector of elements to be sorted. If NULL, it becomes all of the unique elements in ‘x[1:2,]’. |
‘spsort’ steps through rows of ‘x’ identifying the positions of the leading and trailing elements in each rule. If the leading element in the rule does not precede the trailing element in L, its position in L is moved to just ahead of the trailing element. If all of the possible precedence rules for the vector L are specified, the sorting will be unique. In most cases, the order of the result will depend upon the initial order of L and the order of the precendence rules.
The vector ‘L’ sorted by the rules in ‘x’.
Jim Lemon
# Pedro's example
Smaller<-c("ASD", "DFE", "ASD", "SDR", "EDF", "ASD")
Larger<-c("SDR", "EDF", "KLM", "KLM", "SDR", "EDF")
matComp<-cbind(Smaller,Larger)
spsort(matComp)
# scramble the order of rules
nmatrows<-nrow(matComp)
spsort(matComp[sample(1:nmatrows,nmatrows),])
# David Urbina's example
priors<-c("A","B","C","C","D","E","E","F","G")
posts<-c("E","H","A","D","E","B","F","G","H")
dinnerMat<-cbind(priors,posts)
spsort(dinnerMat)
# add the condition that the taquitos must precede the guacamole
dinnerMat<-rbind(dinnerMat,c("G","B"))
spsort(dinnerMat)
# scramble the rows
nmatrows<-nrow(dinnerMat)
spsort(dinnerMat[sample(1:nmatrows,nmatrows),])