https://github.com/hyrodium/basicbsplinefitting.jl

https://github.com/hyrodium/basicbsplinefitting.jl

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• Host: GitHub
• URL: https://github.com/hyrodium/basicbsplinefitting.jl
• Owner: hyrodium
• License: mit
• Created: 2023-01-06T14:55:58.000Z (about 2 years ago)
• Default Branch: main
• Last Pushed: 2024-12-31T18:06:14.000Z (22 days ago)
• Last Synced: 2025-01-18T12:20:24.159Z (4 days ago)
• Language: Julia
• Size: 540 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# BasicBSplineFitting

[![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://hyrodium.github.io/BasicBSpline.jl/dev/math-fitting/)

[![Coverage](https://codecov.io/gh/hyrodium/BasicBSplineFitting.jl/branch/main/graph/badge.svg)](https://codecov.io/gh/hyrodium/BasicBSplineFitting.jl)

This package provides `fittingcontrolpoints` and related functions.

These functions have been moved from [BasicBSpline.jl v0.9.0](https://github.com/hyrodium/BasicBSpline.jl/releases/tag/v0.9.0).

## Fitting B-spline manifold

[Try on Desmos graphing calculator!](https://www.desmos.com/calculator/2hm3b1fbdf)

```julia

using BasicBSplineFitting

p1 = 2

p2 = 2

k1 = KnotVector(-10:10)+p1*KnotVector([-10,10])

k2 = KnotVector(-10:10)+p2*KnotVector([-10,10])

P1 = BSplineSpace{p1}(k1)

P2 = BSplineSpace{p2}(k2)

f(u1, u2) = SVector(2u1 + sin(u1) + cos(u2) + u2 / 2, 3u2 + sin(u2) + sin(u1) / 2 + u1^2 / 6) / 5

a = fittingcontrolpoints(f, (P1, P2))

M = BSplineManifold(a, (P1, P2))

save_png("fitting.png", M, unitlength=50, xlims=(-10,10), ylims=(-10,10))

```

![](docs/src/img/fitting_desmos.png)

![](docs/src/img/fitting.png)

If the knot vector span is too coarse, the approximation will be coarse.

```julia

p1 = 2

p2 = 2

k1 = KnotVector(-10:5:10)+p1*KnotVector([-10,10])

k2 = KnotVector(-10:5:10)+p2*KnotVector([-10,10])

P1 = BSplineSpace{p1}(k1)

P2 = BSplineSpace{p2}(k2)

f(u1, u2) = SVector(2u1 + sin(u1) + cos(u2) + u2 / 2, 3u2 + sin(u2) + sin(u1) / 2 + u1^2 / 6) / 5

a = fittingcontrolpoints(f, (P1, P2))

M = BSplineManifold(a, (P1, P2))

save_png("fitting_coarse.png", M, unitlength=50, xlims=(-10,10), ylims=(-10,10))

```

![](docs/src/img/fitting_coarse.png)

## Draw smooth vector graphics

```julia

p = 3

k = KnotVector(range(-2π,2π,length=8))+p*KnotVector(-2π,2π)

P = BSplineSpace{p}(k)

f(u) = SVector(u,sin(u))

a = fittingcontrolpoints(f, P)

M = BSplineManifold(a, P)

save_svg("sine-curve.svg", M, unitlength=50, xlims=(-2,2), ylims=(-8,8))

save_svg("sine-curve_no-points.svg", M, unitlength=50, xlims=(-2,2), ylims=(-8,8), points=false)

```

![](docs/src/img/sine-curve.svg)

![](docs/src/img/sine-curve_no-points.svg)

This is useful when you edit graphs (or curves) with your favorite vector graphics editor.

![](docs/src/img/inkscape.png)

See [Plotting smooth graphs with Julia](https://forem.julialang.org/hyrodium/plotting-smooth-graphs-with-julia-6mj) for more tutorials.