Here is the next (and probably last) version of the emacs bicycle gearing
program. It now provides a choice of plain text table output, or LaTeX
source output. The LaTeX option produces a nice compact document which
you can take with you on your bike if you're really into it.
Comments, improvements, and bug reports are always most welcome:
bnew...@alum.mit.edu
See you on the road!
;;; bike.el
;
; version 0.2 05-July-1999
;
; Calculate bicycle gearing. Yes, there are a million of these programs
; around, but none for emacs. This one is bare bones and just gives you
; an ugly tabular output in the buffer "*Gear Inches*". There is an
; advantage to this. You can go to this buffer, then evaluate
;
; (calc-grab-rectangle (goto-char (point-min)) (goto-char point-max))
;
; to drop the output into an Emacs Calculator array, after which you can do
; all the postprocessing you ever dreamed about, including plotting.
; The same data file can be used, with some processing, for your
; favorite plotting program such as Gnuplot.
;
; LaTeX output is now an option. It is an either/or proposition, either
; the ugly but useful text table or LaTeX source. LaTeX output more or
; less assumes you have the auctex package installed, or at least
; something that gives you a LaTeX mode (lacking which, this program
; will fail unless you comment out the (latex-mode) line down below).
;
; Usage of this program is really self-explanatory. It should be byte-
; compiled and loaded prior to invoking with M-x bike-gears. The only
; weirdness is that output of chainwheel and cassette calculations are
; in the opposite order from the input order.
;
; Ideas, fixes, and bug reports are welcome at
;
; bnew...@alum.mit.edu
;
; There is no guarantee of support. Use of this program is at your own
; risk. The author assumes no liability for anything whatsoever.
;
; This program is released into the public domain.
(defun bike-gears () "Calculate bicycle gearing" (interactive)
(setq cw (string-to-list (read-string
"Enter chainwheel teeth separated by a space: ")))
(setq cas (string-to-list (read-string
"Enter cassette teeth separated by a space: ")))
(setq wh (float (string-to-number (read-string "Enter wheel size: "))))
(setq latex-or-table (yes-or-no-p "LaTeX output? "))
; No reuse. Save in-between if you want intermediate results.
(if (get-buffer "*Gear Inches*")
(kill-buffer "*Gear Inches*"))
(if (get-buffer "bikegear.tex")
(kill-buffer "bikegear.tex"))
(setq gear-buffer (get-buffer-create "*Gear Inches*"))
; Preamble if LaTeX.
(cond ( latex-or-table
(setq title (read-string "Enter title for table: "))
(save-excursion
(set-buffer gear-buffer)
; LaTeX headers
(insert "\\documentclass[12pt]{article}\n")
(insert "\\begin{document}\n")
(insert "\\thispagestyle{empty}\n")
(insert "\\begin{center}\n")
(insert "{\\bf\\Large Bicycle Gearing Chart} \\\\ \n")
(insert "{\\bf\\Large ")
(insert title)
(insert "} \\\\ \n")
(insert "\\vspace{.5in}\n")
(insert "{\\large Wheel Size ")
(insert (format "%.2f" wh))
(insert "} \\\\ \n")
(insert "\\vspace{.1in}\n")
; Now the cassette stuff and the table setup. Ugga-bugga.
(insert "\\begin{tabular}{|r|") ; column for chainwheels
(setq castemp cas)
(while
(setq casnow (car castemp))
(setq castemp (cdr castemp))
(insert "r|")
)
(insert "}\n\\hline \n")
(setq castemp cas)
(while
(setq casnow (car castemp))
(setq castemp (cdr castemp))
(insert " & ")
(insert casnow)
)
(insert " \\\\ \\hline\n")
)
))
(while
(setq cwnow (car cw))
(setq cw (cdr cw))
(setq castemp cas)
; Start of chainwheel group, begin line.
(cond (latex-or-table
(save-excursion
(set-buffer gear-buffer)
(goto-char (point-max))
(insert cwnow)
)))
(while
(setq casnow (car castemp))
(setq castemp (cdr castemp))
(setq ginches (* wh (/ (float (string-to-number cwnow))
(float (string-to-number casnow)))))
(save-excursion
(set-buffer gear-buffer)
(goto-char (point-max))
(cond ( (not latex-or-table)
(insert cwnow)
(insert " ")
(insert casnow)
(insert " ")
(insert (format "%.2f" ginches))
(insert "\n")
)
(t
(insert " & ")
(insert (format "%.2f" ginches))
))
)
)
; End of chainwheel group, close out line.
(cond ( latex-or-table
(save-excursion
(set-buffer gear-buffer)
(goto-char (point-max))
(insert " \\\\ \\hline \n")
)))
)
; Postamble if LaTeX
(cond ( latex-or-table
(save-excursion
(set-buffer gear-buffer)
(goto-char (point-max))
(insert "\\end{tabular}\n")
(insert "\\end{center}\n")
(insert "\\end{document}\n")
(goto-char (point-min))
(latex-mode)
(write-file "bikegear.tex")
)))
(switch-to-buffer gear-buffer)
)
(defun string-to-list (intext) "parse blank separated tokens from string"
; This is really ugly, and I can't believe I'm unable to locate stock code
; for this type of parsing. Can anyone help?
; UPDATE: I've received a replacement from a kind person in Germany but
; have yet to install it...
(setq outlist (list ()))
(setq pointer 0)
(setq token " ")
(setq doing 0)
(while
(< pointer (length intext))
(cond
( (= doing 0)
(cond
( (not (eq " " (substring intext pointer (1+ pointer))))
(setq doing 1)
(setq token (substring intext pointer (1+ pointer))))))
(t
(cond
( (not (string= " " (substring intext pointer (1+ pointer))))
(setq token (concat token
(substring intext pointer (1+ pointer)))))
(t
(setq outlist (cons token outlist ))
(setq doing 0)
(setq token " "))))
)
(setq pointer (1+ pointer))
)
(if (not (string= token " "))
(setq outlist (cons token outlist))))
;;; end of bike.el
