Mercurial > octave-nkf
diff scripts/polynomial/splinefit.m @ 14551:60ed9260399a
Improve/correct documentation for splinefit.m
* splinefit.m: Clarify and correct documentation.
* doc/interpreter/poly.txi: ditto.
author | Ben Abbott <bpabbott@mac.com> |
---|---|
date | Wed, 11 Apr 2012 19:34:53 -0400 |
parents | 8985cbbd2fe4 |
children | cd375519eab0 |
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--- a/scripts/polynomial/splinefit.m Wed Apr 11 15:40:01 2012 -0400 +++ b/scripts/polynomial/splinefit.m Wed Apr 11 19:34:53 2012 -0400 @@ -27,9 +27,9 @@ ## may be evaluated using @code{ppval}. ## ## @deftypefnx {Function File} {@var{pp} =} splinefit (@var{x}, @var{y}, @var{p}) -## @var{p} is a positive integer defining the number of linearly spaced -## intervals along @var{x}. @var{p} is the number of intervalas and -## @var{p}+1 is the number of breaks. +## @var{p} is a positive integer defining the number of intervals along @var{x}, +## and @var{p}+1 is the number of breaks. The number of points in each interval +## differ by no more than 1. ## ## @deftypefnx {Function File} {@var{pp} =} splinefit (@dots{}, "periodic", @var{periodic}) ## @deftypefnx {Function File} {@var{pp} =} splinefit (@dots{}, "robust", @var{robust}) @@ -53,21 +53,21 @@ ## outlying data. Values close to unity may cause instability or rank ## deficiency. ## -## @var{order} sets the order polynomials used to construct the spline. +## The splines are constructed of polynomials with degree @var{order}. ## The default is a cubic, @var{order}=3. A spline with P pieces has ## P+@var{order} degrees of freedom. With periodic boundary conditions ## the degrees of freedom are reduced to P. ## -## The optional property, @var{constraints}, is a structure specifying +## The optional property, @var{constaints}, is a structure specifying ## linear constraints on the fit. The structure has three fields, "xc", ## "yc", and "cc". ## ## @table @asis ## @item "xc" -## x-locations of the constraints (vector) with a size identical to @var{x}. +## Vector of the x-locations of the constraints. ## @item "yc" -## Constraining values with a size identical to @var{y}. The default -## is an array of zeros. +## Constaining values at the locations, @var{xc}. +## The default is an array of zeros. ## @item "cc" ## Coefficients (matrix). The default is an array of ones. The number of ## rows is limited to the order of the piece-wise polynomials, @var{order}. @@ -79,10 +79,10 @@ ## @example ## @group ## @tex -## $cc(1,j) \cdot y(x) + cc(2,j) \cdot y\prime(x) + ... = yc(:,\dots,:,j), \quad x = xc(j)$. +## $cc(1,j) \cdot y(xc(j)) + cc(2,j) \cdot y\prime(xc(j)) + ... = yc(:,\dots,:,j)$. ## @end tex ## @ifnottex -## cc(1,j) * y(x) + cc(2,j) * y'(x) + ... = yc(:,...,:,j), x = xc(j). +## cc(1,j) * y(xc(j)) + cc(2,j) * y'(xc(j)) + ... = yc(:,...,:,j). ## @end ifnottex ## @end group ## @end example @@ -130,7 +130,7 @@ %! y = sin (x) + 0.1 * randn (size (x)); %! % Breaks %! breaks = [0:5, 2*pi]; -%! % Constraints: y(0) = 0, y"(0) = 1 and y(3) + y"(3) = 0 +%! % Constraints: y(0) = 0, y'(0) = 1 and y(3) + y"(3) = 0 %! xc = [0 0 3]; %! yc = [0 1 0]; %! cc = [1 0 1; 0 1 0; 0 0 1];