Questions on the spline-related functions of Mathematica (BezierCurve[], BSplineCurve[], etc.), or related to the theory and use of splines in Mathematica.
Questions tagged [splines]
195 questions
6
votes
1 answer
How to evaluate BSplineFunction
I have the following code to plot value of a bspline curve but it doesn't evaluate when I specify weights and knots and I'm not sure what's going wrong, the weights and knots vectors have the correct length (and if I change them I get an error) but…
mkm
- 223
- 1
- 6
4
votes
1 answer
Unexpected behavior of BSplineFunction and BezierFunction
$Version
ParametricPlot[BezierFunction[RandomInteger[100,{3,2}]][t],{t,0,1}]
10.4.1 for Microsoft Windows (64-bit) (April 17, 2016)
Crazy result.But the documentation have not any specification for this.And the BezierFunction and BSplineFunction…
yode
- 26,686
- 4
- 62
- 167
3
votes
1 answer
BSpline weights
I changed the weights of my points, but nothing has changed. What should I do to solve this problem?
k = {{{16.24, 44.3486, 642}, {16.24, 44.3652, 625}, {16.24, 44.3818,
717}, {16.24, 44.3984, 940}, {16.24, 44.415, 955}, {16.24,
44.4316,…
Pete
- 53
- 2
3
votes
1 answer
how to PiecewiseExpand BSplineBasis to get Basis matrices of uniform B-splines presented in the paper?
As we all know, the definition of B-spline contains the B-spline basis function, which has the recursive form
$B_{j,k}$ is the j-th degree $k-1$ polynomial. It has nonzeros only in interval $[t_j,t_{j+k})$ which contains $k$ spans…
eason
- 197
- 5
2
votes
1 answer
Different results with BSplineSurface and BSplineFunction
There seems to be some differences when plotting a surface with BSplineSurface and with BSplineFunction.
Points={...}
A=BSplineSurface[Points]
B=BSplineFunction[Points]
PlotA=Graphics3D[A]
PlotB=ParametricPlot3D[B[u,v],{u,0,1},{v,0,1}]
Notice the…
Art
- 141
- 6
2
votes
1 answer
How to find if x-y point falls within a closed BSplineCurve
Here's a simple Manipulate with a closed BSplineCurve, and a Locator.
Manipulate[Graphics[
{BSplineCurve[{{0.5, 0.05}, {1.05, 0.7}, {0.4, 1.5},
{-1.15,0.85}, {-0.75, 0.02}, {-0.93, -1}, {0.2, -1.3}, {1.05, -0.83}},
SplineClosed -> True]}],{pt,…
rhomboidRhipper
- 856
- 4
- 7
2
votes
1 answer
BSplineSurface problem
Why does the result of this function is straight line.If problem is in the order of my points, what order is correct?
l = {{{16.24, 44.3486, 642}, {16.24, 44.3652, 625}, {16.24, 44.3818,
717}, {16.24, 44.3984, 940}, {16.24, 44.415, 955},…
Pete
- 53
- 2
2
votes
3 answers
Coordinates of spline plot using ArcLength mesh function
The following code produces a 3D spline with equidistant interpolation points:
Needs["Splines`"];
f = SplineFit[{{0, 0, 3}, {2, 0, 3}, {2, 2, 1}, {0, 1, 0}}, Cubic];
plot = ParametricPlot3D[f[t], {t, 0, 3},
MeshFunctions -> {"ArcLength"}, Mesh ->…
Jaka Belec
- 23
- 4
2
votes
1 answer
Inverse function does not get evaluated
I have a B-spline function, which is a function that is defined as a weighted sum of BSplineBasis function:
p = 2;
knotvector := {0, 0, 0, 0.25, 0.5, 0.75, 1, 1, 1};
n := Length[knotvector] - p - 1;
controlvector := {0, .2, .4, .6, .8, 1};
m[\[Xi]_]…
Ruben
- 175
- 4
1
vote
3 answers
Variables substitution in a B-Spline function
I have the following identity mapping expressed by tensor-product B-spline basis functions:
pts = {{-1, -1}, {0, -1}, {1, -1}, {-1, 0}, {0, 0}, {1, 0}, {-1,1}, {0, 1}, {1, 1}};
k = {-1, -1, 0, 1, 1};
nBasis = Sqrt[Length[pts]];
basisU =…
S. S.
- 13
- 3
0
votes
0 answers
3D interpolation
I have four column data with first 3 column denoting x,y,z and fourth column
energy. x variable is actually angle. Now I want to interpolate over all three indepdent variable (x,y.z) with corresponding energy value. I have done mathematica script…
george
- 71
- 4