From 463d60c57b61e44a45cb1d37df0421824e552f65 Mon Sep 17 00:00:00 2001 From: Carsten Dominik Date: Wed, 3 Mar 2010 13:19:43 +0100 Subject: [PATCH] Improve documentation on calc accuracy in tables Patch by Michael Brand --- doc/org.texi | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/doc/org.texi b/doc/org.texi index 394c66fe9..2760905b0 100644 --- a/doc/org.texi +++ b/doc/org.texi @@ -2129,8 +2129,11 @@ compact. The default settings can be configured using the variable @code{org-calc-default-modes}. @example -p20 @r{switch the internal precision to 20 digits} -n3 s3 e2 f4 @r{normal, scientific, engineering, or fixed display format} +p20 @r{set the internal Calc calculation precision to 20 digits} +n3 s3 e2 f4 @r{Normal, scientific, engineering, or fixed} + @r{format of the result of Calc passed back to Org.} + @r{Calc formatting is unlimited in precision as} + @r{long as the Calc calculation precision is greater.} D R @r{angle modes: degrees, radians} F S @r{fraction and symbolic modes} N @r{interpret all fields as numbers, use 0 for non-numbers} @@ -2140,8 +2143,16 @@ L @r{literal} @end example @noindent -In addition, you may provide a @code{printf} format specifier to -reformat the final result. A few examples: +Unless you use large integer numbers or high-precision-calculation +and -display for floating point numbers you may alternatively provide a +@code{printf} format specifier to reformat the Calc result after it has been +passed back to Org instead of letting Calc already do the +formatting@footnote{The @code{printf} reformatting is limited in precision +because the value passed to it is converted into an @code{integer} or +@code{double}. The @code{integer} is limited in size by truncating the +signed value to 32 bits. The @code{double} is limited in precision to 64 +bits overall which leaves approximately 16 significant decimal digits.}. +A few examples: @example $1+$2 @r{Sum of first and second field}