bpolynomial update from CTAN

git-svn-id: svn://tug.org/texlive/trunk@5644 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 23 insertions, 4 deletions

diff --git a/Master/texmf-dist/metapost/bpolynomial/bpolynomial.mp b/Master/texmf-dist/metapost/bpolynomial/bpolynomial.mp
index 6840bb04038..f1c0129bb94 100644
--- a/Master/texmf-dist/metapost/bpolynomial/bpolynomial.mp
+++ b/Master/texmf-dist/metapost/bpolynomial/bpolynomial.mp
@@ -9,15 +9,21 @@
 
 if known bpolynomial_fileversion: endinput fi;
 string bpolynomial_fileversion;
-bpolynomial_fileversion := "v0.3 (2007/11/26)";
+bpolynomial_fileversion := "v0.4 (2007/11/28)";
 message "Loading bpolynomial " & bpolynomial_fileversion;
 
 
+vardef newBPolynomial@#(expr a, b, c, d)=
+  defineBPolynomial.@#(a, b, c, d);
+  defineBPolynomial.@#'(0, 3a, 2b, c);
+  defineBPolynomial.@#''(0, 0, 6a, 2b);
+  defineBPolynomial.@#'''(0, 0, 0, 6a);
+enddef;
+
 %%% This macro defines two macros @#.eval and @#.getPath.
 %%% Parameters are the coefficients of the polynomial a*x^3 + b*x^2 + c*x + d.
-vardef newBPolynomial@#(expr ca,cb,cc,cd)=
+vardef defineBPolynomial@#(expr ca,cb,cc,cd)=
 numeric @#.a, @#.b, @#.c, @#.d;
-  
   %%% Save coefficients for later access.
   %%% For instance, variable @#.a refers to coefficient a of polynomial @#.
   @#.a := ca;
@@ -25,12 +31,14 @@ numeric @#.a, @#.b, @#.c, @#.d;
   @#.c := cc;
   @#.d := cd;
   
-  %%% Define a macro that returns polynomial values.
+  
+  %%% Define macro that returns values of polynomial @#.
   %%% Parameter is an x value.
   vardef @#.eval(expr x)=
     (((@#.a*x + @#.b)*x + @#.c)*x + @#.d)
   enddef;
   
+  
   %%% Define a macro that returns a path of the polynomial
   %%% on a given intervall [xl, xr].
   vardef @#.getPath(expr xl,xr)=
@@ -63,4 +71,15 @@ numeric @#.a, @#.b, @#.c, @#.d;
     (xA,yA)..controls (xB,yB) and (xC,yC)..(xD,yD)
   enddef;
   
+
+  %%% Define macro that returns a path tangent to @# at point (x, f(x))
+  %%% covering interval (x+xm, x+xp).
+  vardef @#.getTangent(expr x, xm, xp)=
+  save m, y;
+  numeric m, y;
+    m := (3@#.a*x + 2@#.b)*x + @#.c;
+    y := @#.eval(x);
+    (x+xm, y + m*xm) -- (x+xp, y + m*xp)
+  enddef;
+  
 enddef;