On 5/23/2014 3:48 PM, Jeong Dal wrote:
Dear Luigi and listers,Last year, I need to write a text for a linear algebra class. Since there are many \startmatrix … \stopmatrix and matrix calculations, I wrote a lua code which did matrix calculations and writing with a lot of help from this list. Using the code, I can write class materials easily. It is good enough for my purpose. I am not good in Lua coding, so there may be many things to be checked for efficiency and for stability. However, I attached the code because there may be someone who need it. It is also good thing to return what I get from the list back. I hope that you enhance the code for better performance since you are an expert in Lua.
A bit more readable:
matrixOP.symMatrix = function(sym, x, y, nx ,ny) -- symMatrix("a", "m", "n")
local nx = nx or 2
local ny = ny or nx
local function filled(i,y)
local mrow = { }
for j=1,nx do
table.insert(mrow, string.formatters["%s_{%s%s}"](sym,i,j))
end
table.insert(mrow,"\\cdots")
table.insert(mrow,string.formatters["%s_{%s%s}"](sym,i,y))
return mrow
end
local function dummy()
local mrow = { }
for j=1,nx do
table.insert(mrow,"\\vdots")
end
table.insert(mrow,"\\ddots")
table.insert(mrow,"\\vdots")
return mrow
end
--
local mm = { }
for i=1,ny do
table.insert(mm,filled(i,y))
end
table.insert(mm,dummy())
table.insert(mm,filled(x,y))
return mm
end
Also, variable nx, ny:
\ctxlua{matrixOP.write(matrixOP.symMatrix("a","m","n",4,8))}
Maybe this too:
local default = {
left = [[\left(\,]],
right = [[\,\right)]],
}
matrixOP.write = function (t)
context.startmatrix(default)
for _, r in ipairs(t) do
for _, c in ipairs(r) do
context.NC(c)
end
context.NR()
end
context.stopmatrix()
end
matrixOP.writeDet = function(t)
context.startmatrix(default)
for _, r in ipairs(t) do
for _, c in ipairs(r) do
context.NC(c)
end
context.NR()
end
context.stopmatrix()
end
And:
matrixOP.rowMult = function(t, i, m) -- replace i-th row with m*(i-th row)
for k = 1, #t[i] do t[i][k] = m*t[i][k] end
end
matrixOP.rowMultSum = function(t, i, j, m) -- replace i-th row with i-th
row + m*(j-th row)
for k = 1, #t[1] do t[i][k] = t[i][k] + m*t[j][k] end
end
(no need for further speedup as it't non-critical code with neglectable
runtime)
More Luaish (local usage):
matrixOP.transpose = function(m) -- transpose of a matrix
local mT={}
for j = 1, #m[1] do
local mTrow={}
for i=1, #m do
local temp = m[i][j]
table.insert(mTrow, temp)
end
table.insert(mT, mTrow)
end
return mT
end
Don't forget the local here:
matrixOP.inner = function (u, v) -- inner product of two vectors
local temp=0
if #u == #v then
for i=1, #u do
temp = temp + u[i]*v[i]
end
end
return temp
end
and here:
matrixOP.product = function(m1, m2) -- product of two matrices
local m3={}
if #m1[1] == #m2 then
for i = 1, #m1 do
local mrow={}
for j=1, #m2[1] do
local temp = 0
for k=1, #m1[1] do
u = m1[i][k]*m2[k][j]
temp = temp + u
end
table.insert(mrow, temp)
end
table.insert(m3, mrow)
end
end
return m3
end
less code:
matrixOP.searchRow = function(m, i)
local pr = #m + 1
for k=i+1, #m do
if m[k][i] == 0 then
k = k+1
else
pr = k
break
end
end
if pr <= #m then
return pr
else
return 0
end
end
Are you sure this is ok? I've added a copy as you might want to keep the
original table:
matrixOP.upperTri = function(m)
local temp = table.copy(m)
for i=1, #temp-1 do
local pivot = temp[i][i]
if pivot == 0 then
local pRow = matrixOP.searchRow(temp, i)
if pRow==0 then
break
end
matrixOP.rowChange(temp, i, pRow)
sgn=(-1)*sgn
end
for k=i+1, #temp do
matrixOP.rowMultSum(temp, k, i,-temp[k][i]/temp[i][i])
end
end
return temp
end
So then, watch how we use the return value of this one:
matrixOP.determinant = function(m)
if #m ==#m[1]then
local det = 1
local t = matrixOP.upperTri(m)
for i=1,#t do
det = det * t[i][i]
end
return det
else
return 0
end
end
I always thank to this list and to developers of ConTeXt.
Based on the attached I can make a more efficient version that we can then add to the distribution (maybe you need more than this?)
Hans
Best regards, DalyoungMessage: 1 Date: Fri, 23 May 2014 13:44:30 +0200 From: luigi scarso <luigi.sca...@gmail.com> To: mailing list for ConTeXt users <ntg-context@ntg.nl> Subject: Re: [NTG-context] Simple command with variable number of arguments Message-ID: <CAG5iGsCadu33Hw=hphmde+wp1b_fcpjn0caxwjaso+vnqbj...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" On Fri, May 23, 2014 at 11:54 AM, Matthias Weber <matwe...@indiana.edu>wrote:Dear All, I would like to define a command that expands \vector{2,4} % or vector[2,4] if that?s easier to \startpmatrix \NC 2 \NR \NC 4 \NR \stoppmatrix and more generally \vector{2,4,1,7} to \startpmatrix \NC 2 \NR \NC 4 \NR \NC 1 \NR \NC 7 \NR \stoppmatrix Any hints how to achieve this? Thanks,\definemathmatrix [pmatrix] [left={\left(\,},right={\,\right)}] \startluacode document = document or {} document.matthias = document.matthias or {} local function lua_columnvector(a) context.startpmatrix() for i,v in ipairs(a) do context.NC() context(tostring(v)) context.NR() end context.stoppmatrix() end document.matthias.lua_columnvector = document.matthias.lua_columnvector or lua_columnvector \stopluacode \def\columnvector#1{\ctxlua{document.matthias.lua_columnvector(#1)}} \starttext \startformula \columnvector{{1,2,3}} %% watch the double { ! \stopformula \stoptext -- luigi -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.ntg.nl/pipermail/ntg-context/attachments/20140523/569165d6/attachment-0001.html> ------------------------------___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________
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