I use a combination of Java programs and shell scripts. I don't know
whether that is the best way of doing it, I just needed a way that
worked. I'm afraid it isn't generalized at all.

Here's a sample of some Java code, generating the preamble for a LaTeX
"tabular", a table format. "titles" is a List of column headings, and my
objective was a table with equal column widths totaling "totalWidth"
inches. I don't think it will help much unless you understand LaTeX:

  private void putHeader(PrintStream out) {
    out.print("\\begin{tabular}{|");
    int cols = titles.size() + 1;
    double colWidth = totalWidth / cols;
    colWidth = Math.rint(colWidth * 100) / 100;
    for (int i = 0; i < cols; i++) {
      out.print("p{" + colWidth + " in}|");
    }
    out.println("} \\hline");
    out.print("Cut Off\t\t");
    for (Iterator it = titles.iterator(); it.hasNext();) {
      out.print(" & " + it.next() + "\t\t");
    }
    out.println("\\\\ \\hline");
  }

This is a shell script, makedoc, for taking some LaTeX fragments and
packing them with a header and trailer to produce a complete document:

#!/bin/ksh
echo '\\documentclass{article}'
echo '\\begin{document}'
cat $@
echo '\\end{document}'

These are a couple of makefile rules for producing .pdf from pieces of
LaTeX source, using makedoc.

%.pdf: %.sect.tex
    ./makedoc $*.sect.tex >$*.tex
    pdflatex $*.tex

summary.pdf: ${SHORT_SECTIONS}
    ./makedoc $^ >summary.tex
    pdflatex summary.tex

Hope some of this helps.

Patricia