Re: Formatting numbers in LuaTeX

["Peter Münster" <pmlists@free.fr>]

On Sun, Feb 14 2010, Hans Hagen wrote:

>>    sqrt = math.sqrt
>>    pi = math.pi
>>    function my_equation(s, r)
>
> beware, this creates (and possibly overloads) sqrt, pi and my_equation as 
> gobals

Indeed...

The following hack was *not* so quick, but there is a bug somewhere
(a digit is added at the end):

\usemodule[calcmath]
\startluacode
local exp_replacements = {["*"] = "$·$"}
local res_replacements = {["sqrt"] = "math.sqrt", ["π"] = "math.pi"}
userdata = userdata or {}
function userdata.result_as_string(r)
	r = math.floor(1000 * r + 0.5) / 1000
	r = tostring(r)
	tex.write(r:gsub("%.", ","))
end
function userdata.filter_expression(s)
	for k, v in pairs(exp_replacements) do
		s = s:gsub(k, v)
	end
	tex.write(s)
end
function userdata.filter_result(s)
	for k, v in pairs(res_replacements) do
		s = s:gsub(k, v)
	end
	tex.write(s)
end
\stopluacode
\def\calculate#1{%
  \start
    \def\Expression{\ctxlua{userdata.filter_expression("#1")}}
    \def\Result{\ctxlua{userdata.filter_result("#1")}}
    \calcmath{\Expression=\ctxlua{userdata.result_as_string(\Result)}}
  \stop
}
\starttext
\startlines
  \calculate{1+2}
  \calculate{3/2-1}
  \calculate{3*2}
  \calculate{sqrt(2)}
  \calculate{2*π}
\stoplines
\stoptext

Cheers, Peter

-- 
Contact information: http://pmrb.free.fr/contact/


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