On 1/9/2026 11:37 PM, Jeong Dal via ntg-context wrote:
Dear Hans,
Thank you for the correction.
see below
your "decimal j" makes string while a number is expected
here mp.print is clever enough to return a number
label(textext("A"),(
i*u,
lua("mp.print(MP.data[" & decimal i & "][1])")
));
message(lua("mp.print(MP.data[" & decimal i & "][1])"));
Now I got the working code.
It calculates the list of 4-dimensional vectors and draw a line graph
which shows the change of each component of vectors.
Here is the code. There may be several points which can be written more
nicely.
Thanks again.
Best regards,
Dalyoung
\startluacode
local matT = {{0,0,1,1/3},{1,0,0,1/3},{0,1/2,0,1/3},{0,1/2,0,0}}
local matOld = {{1/4},{1/4},{1/4},{1/4}}
local matNew = {}
local matHistory = {}
table.insert(matHistory, matOld)
for i = 1, 15 do
matOld = matHistory[i]
matNew = mtx.product(matT, matOld)
if (i < 5) or (i==14) then
context("${\\mathbf P_{"..tostring(i).."} = }$")
mtx.typeset(matT)context("\\times")mtx.typeset(matOld)
context(" = ") mtx.typeset(matNew) context("\\blank")
end
table.insert(matHistory, matNew)
end
table.save("tempList.lua", matHistory)
\stopluacode
\startplacefigure[reference=fig:PR,title={PageRank 값의 변화}]
{\startMPcode
numeric u, yy; u := 1cm;
pair A[];
path p;
string prob;
color myColor[];
myColor[1] := .7red;
myColor[2] := .7blue;
myColor[3] := .7green;
myColor[4] := .7white;
lua("MP = { } MP.data = table.load('tempList.lua')") ;
for j = 1 upto 4:
for i = 1 upto 15:
yy := lua("mp.print(MP.data[" & decimal i & "][" & decimal j & "])");
A[i] := (i*.7u,yy*15u);
% message(lua("mp.print(MP.data[" & decimal i & "][1])"));
endfor;
p := for i = 1 upto 14 : A[i] -- endfor A[15] ;
prob := substring (0,6) of (decimal yy);
label.rt(textext(char(64+j) & " " & prob),A[15]);
draw p withpen pencircle scaled 1.5pt withcolor myColor[j];
drawpoints p;%[i];
endfor;
\stopMPcode}
\stopplacefigure
You have to be more careful here; you do
MP = { }
which overloaded an official global namespace. That will backfire at
some point.
You still have mtx as global alias without testing if it exists. Don't
do that, because one never knows if context itself will use that
namespace (ctx, mtx ...). Basically we don't expect users or modules to
define global tables at all, and if they to one has it coming. Just use
userdata or moduledata (with subtable) or so.
I'm not going to rewrite your code but here are a few suggestions:
function MP.loadmydata(n)
MP.mydata = table.load(n)
end
function MP.getmydata(i,j)
mp.print(MP.mydata[i][j])
end
and then
% lua("MP = { } MP.data = table.load('tempList.lua')") ;
lua.MP.loadmydata('tempList.lua') ;
with
% yy := lua("mp.print(MP.data[" & decimal i & "][" & decimal j & "])");
yy := lua.MP.getmydata(i,j);
which gives you an easier way to check for instance of the data is ok or
mess with it at the lua end.
Watch how we accept ' as string delimiter ... by default luametafun is
set up to accept ' and " as in lua.
Hans
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!
maillist : [email protected] /
https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
webpage : https://www.pragma-ade.nl / https://context.aanhet.net (mirror)
archive : https://github.com/contextgarden/context
wiki : https://wiki.contextgarden.net
___________________________________________________________________________________
