bezierplot (18jun19)

git-svn-id: svn://tug.org/texlive/trunk@51398 c570f23f-e606-0410-a88d-b1316a301751

5 files changed, 37 insertions, 19 deletions

diff --git a/Master/texmf-dist/doc/lualatex/bezierplot/README b/Master/texmf-dist/doc/lualatex/bezierplot/README
index 38f7ba74266..493bfe5c651 100644
--- a/Master/texmf-dist/doc/lualatex/bezierplot/README
+++ b/Master/texmf-dist/doc/lualatex/bezierplot/README
@@ -8,7 +8,7 @@ points such as extreme points and inflection points and reduces the
 number of used points.
 
 VERSION:
-1.3 2018-09-03
+1.4 2019-06-18
 
 LICENSE:
 The package and the program are distributed on CTAN under the terms of 
diff --git a/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.pdf b/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.pdf
index a74e699da23..c93fd5f1021 100644
--- a/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.pdf
+++ b/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.pdf
diff --git a/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.tex b/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.tex
index a079bce18cf..a1239b6e574 100644
--- a/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.tex
+++ b/Master/texmf-dist/doc/lualatex/bezierplot/bezierplot-doc.tex
@@ -23,7 +23,7 @@
 \section{Introduction}
 \texttt{bezierplot} is a Lua program as well as a (Lua)\LaTeX{} package. This document describes both.
 
-Given a smooth function, \texttt{bezierplot} returns a smooth bezier path written in Ti\emph{k}Z notation (which also matches \MP{}) that approximates the graph of the function. For polynomial functions of degree $\leq 3$ and inverses of them, the approximation is exact. \texttt{bezierplot} finds special graph points such as extreme points and inflection points and reduces the number of used points.
+Given a smooth function, \texttt{bezierplot} returns a smooth bezier path written in Ti\emph{k}Z notation (which also matches \MP{}) that approximates the graph of the function. For polynomial functions of degree $\leq 3$ and inverses of them, the approximation is exact (up to numeric precision). \texttt{bezierplot} finds special graph points such as extreme points and inflection points and reduces the number of used points.
 
 The following example will show a comparison of \textsc{gnuplot} with \verb|bezierplot| for the function $y=\sqrt{x}$ for $0\leq x \leq 5$:
 \begin{center}
@@ -39,7 +39,7 @@ The following example will show a comparison of \textsc{gnuplot} with \verb|bezi
       		\end{scope}
 	\end{tikzpicture}
 \end{center}
-\textsc{gnuplot} used 51 samples (no smoothing) and is still quite inexact at the beginning, whereas \verb|bezierplot| uses 4 points only and is exact!
+\textsc{gnuplot} used 51 samples (no smoothing) and is still quite inexact at the beginning, whereas \verb|bezierplot| uses 4 points only and is exact (up to numeric precision)!
 \section{Installation}
 As \texttt{bezierplot} is written in Lua, the installation depends whether you are using Lua\LaTeX{} or another \LaTeX{} engine.
 \subsection{Installation For Lua\LaTeX{}}
@@ -179,7 +179,7 @@ The following functions and constants are possible:
 \newpage
 %
 \section{Examples of \texttt{bezierplot} in Comparison with \textsc{gnuplot}}
-The following graphs are drawn with \texttt{bezierplot} (black) and \textsc{gnuplot} (red). \textsc{gnuplot} used 1000 samples per example. The functions are given below the pictures (left: bezierplot, right: \textsc{gnuplot}).
+The following graphs are drawn with \texttt{bezierplot} (black) and \textsc{gnuplot} (red). You may not recognize the red behind the black unless you zoom in. \textsc{gnuplot} used 1000 samples per example. The functions are given below the pictures (left: bezierplot, right: \textsc{gnuplot}).
 \begin{multicols}{3}
 \graphcomparison{0.32*x-0.7}{0.32*x-0.7}
 \graphcomparison{-x^2+4}{-x**2+4}
diff --git a/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.lua b/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.lua
index af7dd887b85..382da2d74ea 100755
--- a/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.lua
+++ b/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env lua
 -- Linus Romer, published 2018 under LPPL Version 1.3c
--- version 1.3 2018-09-03
+-- version 1.4 2019-06-18
 abs = math.abs
 acos = math.acos
 asin = math.asin
@@ -15,6 +15,24 @@ sqrt = math.sqrt
 tan = math.tan
 huge = math.huge
 
+-- just a helper for debugging:
+local function printdifftable(t)
+	for i = 1,#t do
+		for j = 1, 6 do
+			if j < 5 then
+				io.write(t[i][j].." ")
+			else
+				if t[i][j] then
+					io.write("true ")
+				else
+					io.write("false ")
+				end
+			end
+		end
+		io.write("\n")
+	end
+end
+
 -- cube root defined for all real numbers x
 function cbrt(x)
 	if x < 0 then
@@ -66,7 +84,7 @@ local function diffgraph(func,graph,h)
 	local l = #graph
 	if l < 4 then -- this is not worth the pain...
 		for i = 1, l do 
-			table.insert(dgraph,{graph[i][1],graph[i][2],0,0,0,0})
+			table.insert(dgraph,{graph[i][1],graph[i][2],0,0,false,false})
 		end
 	else
 		local yh = func(graph[1][1]-h)
@@ -540,7 +558,12 @@ local function graphtobezierapprox(f,g,starti,endi,maxerror)
 				err = abs(ya-f(xa))
 			end
 		end
-		if err <= maxerror then
+		if (err <= maxerror)
+		and qx > -math.huge and qx < math.huge
+		and qy > -math.huge and qy < math.huge
+		and rx > -math.huge and ry < math.huge
+		and sx > -math.huge and sy < math.huge
+		then
 			return {qx,qy,rx,ry,sx,sy}
 		else
 			-- search for an intermediate point where the graph has the same
@@ -561,7 +584,11 @@ local function graphtobezierapprox(f,g,starti,endi,maxerror)
 			end
 			return left
 		end
-	else
+	elseif qx > -math.huge and qx < math.huge
+	and qy > -math.huge and qy < math.huge
+	and rx > -math.huge and ry < math.huge
+	and sx > -math.huge and sy < math.huge
+	then
 		return {qx,qy,rx,ry,sx,sy}
 	end
 end
@@ -586,16 +613,6 @@ local function graphtobezier(g,starti,endi,isinverse)
 	end
 end
 
--- just for debugging:
-local function printtable(t)
-	for i = 1,#t do
-		for j = 1, #t[i] do
-			io.write(t[i][j].." ")
-		end
-		io.write("\n")
-	end
-end
-
 -- main function
 function bezierplot(functionstring,xminstring,xmaxstring,yminstring,ymaxstring,samplesstring,notation)
 	local fstringreplaced = string.gsub(functionstring, "%*%*", "^")
@@ -840,6 +857,7 @@ function bezierplot(functionstring,xminstring,xmaxstring,yminstring,ymaxstring,s
 			-- go through the connected parts
 			for part = 1, #graphs do 
 				local dg = diffgraph(f,graphs[part],xstep)
+				--printdifftable(dg) -- for debugging
 				bezierpoints[#bezierpoints+1] = {dg[1][1],dg[1][2]}
 				local startindex = 1
 				for k = 2, #dg do
diff --git a/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.sty b/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.sty
index 4584777e476..94be30b4dce 100644
--- a/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.sty
+++ b/Master/texmf-dist/tex/lualatex/bezierplot/bezierplot.sty
@@ -1,5 +1,5 @@
 \NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{bezierplot}[2018/09/03 bezierplot]
+\ProvidesPackage{bezierplot}[2019/06/18 bezierplot]
 \RequirePackage{xparse}
 \RequirePackage{iftex}
 \ifLuaTeX