>From da8e9914d4f63cb3bfa6e7beacd8ee762044b2e6 Mon Sep 17 00:00:00 2001 From: Eric Abrahamsen Date: Thu, 18 Dec 2014 18:04:00 +0800 Subject: [PATCH] Mention calc-units in the spreadsheet documentation * doc/org.texi: Outline using units in tables, link to appropriate part of the Calc manual. --- doc/org.texi | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/doc/org.texi b/doc/org.texi index 7c464ca..aae0537 100644 --- a/doc/org.texi +++ b/doc/org.texi @@ -2756,6 +2756,26 @@ should be padded with 0 to the full size. You can add your own Calc functions defined in Emacs Lisp with @code{defmath} and use them in formula syntax for Calc. +Calc also comes with support for unit calculations, via the @code{calc-units} +package. For a complete list of recognized units, call address@hidden Units can be specified with or without a space +between the number and the unit name, eg @samp{2 ft} is the same as address@hidden Rates are handled automatically: multiplying @samp{3 m/s} by two +will give @samp{6 m / s}. By default, @code{calc-units} only defines one +units-related function for use in tables, @code{usimplify}, which can take an +expression such as @samp{42 km / 2.5 h} and return @samp{16.8 km / hr}. +Another useful function to define might be @code{math-convert-units}, eg: + address@hidden +(defmath uconv (expr target-units &optional pure) + (math-convert-units expr target-units pure)) address@hidden example + +Which would allow you to use @samp{uconv($1, ft)} to, for example, convert a +distance specified in the cell @samp{$1} into feet. The optional 'pure +argument strips the units designator from the number in the results. address@hidden, Operating on Units,,calc}. + @node Formula syntax for Lisp @subsection Emacs Lisp forms as formulas @cindex Lisp forms, as table formulas -- 2.2.0