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Fractals/curves
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Curves
definition
2D scalar field
level curves
field lines
boundary
component of Parameter plane (Mandelbrot set, exterior of M set)
of component of Mandebrot set
of dynamic plane (Fatou components , Julia set)
components of Julia set
types
Cyrve typesgeeksforgeeks : graphics-curve-in-computer-graphics
defined by equation
Implicit curves
Explicit curves
Parametric curves
spline curves
Bezier curves
B-spline curves
Level curves
Level cures:
edge detection of level sets gives boundaries
tracing equilevel curves
computes contour polygons by applying marching squares to a rectangular array of numeric values ( d3-contour library )
inverse iteration of closed curve ( circle) around attractor
Level curves of 2D scalar field:
equipotential lines ( isocurves , contour lines)
boundary
filed lines ( rays) = level curves of external angle
Field lines
parameter plane
external rays on the parameter plane = parameter rays
internal rays
dynamic plane
external rays on dynamic plane = dynamic rays
internal rays
The field lines of a vector field ( the gradient of a scalar field ) can be drawn without solving a DE, because the gradient of a scalar field is orthogonal to the level curves of the scalar field. In general they can only
be solved numerically using a computer.
the most convenient way to get a metric perpendicular to equipotentials is to take the arctan2 of the point at bailout. That gives field lines (or lines of longitude) that branch at each iteration boundary in exterior regions. In interior regions they do not branch, so it's easy to apply continuous textures. ( xenodreambuie) xenodreambui
See also
Category:External rays : images in Commons, some with src code
Category:Level_set_method in commons
2D algorithms
axismaps: go-with-the-flow
awoodruff: relief-flow
wind map and code
References