Re: plot data from file: cld

[Hans Hagen <pragma@wxs.nl>]

On 1/4/2015 6:04 AM, Akira Kakuto wrote:
> Dear John,
>
>> How to make this a polygon?
>
> An example:
>
> \starttext
> \startluacode
> local metafun = context.metafun
> metafun.start()
> io.input("DATA")
> local i, j
> local x, y, s, t1, t2
> i = 1
> x={}
> y={}
> s="draw "
> while true do
>   x[i], y[i] = io.read("*n", "*n")
>   if not x[i] then break end
>   metafun("filldraw fullcircle scaled 2mm shifted(%dcm,%dcm);",x[i],y[i])
>   i = i + 1
> end
> i = i - 1
> for j = 1, i do
>   t1 = tostring(x[j])
>   t2 = tostring(y[j])
>   s = s.."("..t1.."cm,"..t2.."cm)--"
> end
> t1 = tostring(x[1])
> t2 = tostring(y[1])
> s = s.."("..t1.."cm,"..t2.."cm)"
> s = s.." withpen pencircle scaled 1bp;"
> metafun(s)
> metafun.stop()
> \stopluacode
> \stoptext

Here is a bit more compact version. A path can normally nicely be concat 
using "--" or ".." and we have a metafun helper drawpoints.

\starttext
\startluacode
context.metafun.start()
local split = utilities.parsers.csvsplitter { separator = " " }
local data = split(io.loaddata("data.txt"))
for i=1,#data do
     data[i] = string.formatters["(%s,%s)"](unpack(data[i]))
end
context.metafun("path p ; p := (%s -- cycle) scaled cm 
;",table.concat(data,"--"))
context.metafun("draw       p withpen pencircle scaled 0.25mm ;")
context.metafun("drawpoints p withpen pencircle scaled 2.00mm ;")
context.metafun.stop()
\stopluacode
\stoptext




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                                           Hans Hagen | PRAGMA ADE
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