Re: [NTG-context] Lua to Context Table

2 Aug 2014


      On Sat, 2 Aug 2014, luigi scarso wrote:
...
On Sat, Aug 2, 2014 at 12:59 AM, John Kitzmiller  wrote:
...
Here is Lua code that prints the first nine fibonacci numbers:
local function fib(n)
  f={1,1}
  for i=3,9 do
    f[i]=f[i-1]+f[i-2]
  end
  return(f[n])
end
for n=1,9 do print(fib(n)) end
Here is Context+Lua that prints 3 x 3 table of the first nine natural
numbers:
\starttext
\setupTABLE[each][each][frame=off,align=left,width=4em,height=2em]
\startluacode
context.bTABLE()
for j = 0, 2 do
  context.bTR()
    for k = 1, 3 do
      context.bTD()
        context(3*j+k)
      context.eTD()
    end
  context.eTR()
end
context.eTABLE()
\stopluacode
\stoptext
How can these be combined to print a 3 x 3 table of the first nine
fibonacci numbers?
I have tried a couple of ways to iterate over the lua table f in the most
indented line of context, looked at what pertinent threads I could find,
the Wiki entries, CLD, and tried Aditya's method from Stack Exchange; I am
missing something.
You have a *global* table f  that collides with the internals of context
local function fib(n)
 f={1,1}
 for i=3,9 do
   f[i]=f[i-1]+f[i-2]
 end
 return(f[n])
end
\starttext
\setupTABLE[each][each][frame=off,align=left,width=8em,height=2em]
\startluacode
local function fib(n)
 local f={1,1}
 for i=3,9 do
   f[i]=f[i-1]+f[i-2]
 end
 return(f[n])
end
context.bTABLE()
for j = 0, 2 do
 context.bTR()
   for k = 1, 3 do
     context.bTD()
       context("fib(%s)=%s" ,3*j+k, fib(3*j+k) )
     context.eTD()
   end
 context.eTR()
end
context.eTABLE()
\stopluacode
\stoptext
This version recomputes all fibnocci numbers from scrach each time. Here 
is a memoized version:

\setupTABLE[each][each][frame=off,align=left,width=8em,height=2em]
\starttext

\startluacode
local fibs = {1, 1}
local function fib(n)
   if fibs[n] == nil then
     print(">>>>", "Computing fib:" .. n)
     fibs[n] = fib(n-1) + fib(n-2)
   end

   return fibs[n]
end

context.bTABLE()
for j = 0, 2 do
   context.bTR()
     for k = 1, 3 do
       context.bTD()
         context("fib(%s)=%s" ,3*j+k, fib(3*j+k) )
       context.eTD()
     end
   context.eTR()
end
context.eTABLE()
\stopluacode
\stoptext


Aditya

Re: [NTG-context] Lua to Context Table

Aditya Mahajan