[R Code] Split long names in format.ftable

Dear List members,


I wrote some code to split long names in format.ftable. I hope it will 
be useful to others as well.


Ideally, this code should be implemented natively in R. I will provide 
in the 2nd part of the mail a concept how to actually implement the 
code in R. This may be interesting to R-devel as well.


### Helper function

# Split the actual names

split.names = function(names, extend=0, justify="Right", 
blank.rm=FALSE, split.ch = "\n", detailed=TRUE) {
??? justify = if(is.null(justify)) 0 else pmatch(justify, c("Left", 
"Right"));
??? str = strsplit(names, split.ch);
??? if(blank.rm) str = lapply(str, function(s) s[nchar(s) > 0]);
??? nr? = max(sapply(str, function(s) length(s)));
??? nch = lapply(str, function(s) max(nchar(s)));
??? chf = function(nch) paste0(rep(" ", nch), collapse="");
??? ch0 = sapply(nch, chf);
??? mx? = matrix(rep(ch0, each=nr), nrow=nr, ncol=length(names));
??? for(nc in seq(length(names))) {
??? ??? n = length(str[[nc]]);
??? ??? # Justifying
??? ??? s = sapply(seq(n), function(nr) paste0(rep(" ", nch[[nc]] - 
nchar(str[[nc]][nr])), collapse=""));
??? ??? s = if(justify == 2) paste0(s, str[[nc]]) else 
paste0(str[[nc]], s);
??? ??? mx[seq(nr + 1 - length(str[[nc]]), nr) , nc] = s;
??? }
??? if(extend > 0) {
??? ??? mx = cbind(mx, matrix("", nr=nr, ncol=extend));
??? }
??? if(detailed) attr(mx, "nchar") = unlist(nch);
??? return(mx);
}

### ftable with name splitting
# - this code should be ideally integrated inside format.ftable;
ftable2 = function(ftbl, print=TRUE, quote=FALSE, ...) {
??? ftbl2 = format(ftbl, quote=quote, ...);
??? row.vars = names(attr(ftbl, "row.vars"))
??? nr = length(row.vars);
??? nms = split.names(row.vars, extend = ncol(ftbl2) - nr);
??? ftbl2 = rbind(ftbl2[1,], nms, ftbl2[-c(1,2),]);
??? # TODO: update width of factor labels;
??? # - new width available in attr(nms, "nchar");
??? if(print) {
??? ??? cat(t(ftbl2), sep = c(rep(" ", ncol(ftbl2) - 1), "\n"))
??? }
??? invisible(ftbl2);
}

I have uploaded this code also on Github:

https://github.com/discoleo/R/blob/master/Stat/Tools.Data.R


B.) Detailed Concept
# - I am ignoring any variants;
# - the splitting is actually done in format.ftable;
# - we set only an attribute in ftable;
ftable = function(..., split.ch="\n") {
?? [...]
?? attr(ftbl, "split.ch") = split.ch; # set an attribute "split.ch"
?? return(ftbl);
}

format.ftable(ftbl, ..., split.ch) {
if(is.missing(split.ch)) {
?? # check if the split.ch attribute is set and use it;
} else {
?? # use the explicitly provided split.ch: if( ! is.null(split.ch))
}
?? [...]
}


C.) split.names Function

This function may be useful in other locations as well, particularly 
to split names/labels used in axes and legends in various plots. But I 
do not have much knowledge of the graphics engine in R.


Sincerely,


Leonard