ImplicitCurve

Usage (signatures)

board.create('implicitcurve', [f, dfxopt, dfyopt, rangexopt, rangeyopt]);

Parameters

Name	Type	Attributes	Default	Description
`f`	function \| String			Function of two variables for the left side of the equation \(f(x,y)=0\). If f is supplied as string, it has to use the variables 'x' and 'y'.
`dfx`	function \| String	<optional>	`null`	Optional partial derivative in respect to the first variable If dfx is supplied as string, it has to use the variables 'x' and 'y'.
`dfy`	function \| String	<optional>	`null`	Optional partial derivative in respect to the second variable If dfy is supplied as string, it has to use the variables 'x' and 'y'.
`rangex`	Array \| function	<optional>	`boundingbox`	Optional array of length 2 of the form [x_min, x_max] setting the domain of the x coordinate of the implicit curve. If not supplied, the board's boundingbox (+ the attribute 'margin') is taken.
`rangey`	Array \| function	<optional>	`boundingbox`	Optional array of length 2 of the form [y_min, y_max] setting the domain of the y coordinate of the implicit curve. If not supplied, the board's boundingbox (+ the attribute 'margin') is taken.

Examples

var f, c;
  f = (x, y) => 1 / 16 * x ** 2 + y ** 2 - 1;
  c = board.create('implicitcurve', [f], {
      strokeWidth: 3,
      strokeColor: JXG.palette.red,
      strokeOpacity: 0.8
  });

var a, c, f;
 a = board.create('slider', [[-3, 6], [3, 6], [-3, 1, 3]], {
     name: 'a', stepWidth: 0.1
 });
 f = (x, y) => x ** 2 - 2 * x * y - 2 * x + (a.Value() + 1) * y ** 2 + (4 * a.Value() + 2) * y + 4 * a.Value() - 3;
 c = board.create('implicitcurve', [f], {
     strokeWidth: 3,
     strokeColor: JXG.palette.red,
     strokeOpacity: 0.8,
     resolution_outer: 20,
     resolution_inner: 20
 });

var c = board.create('implicitcurve', ['abs(x * y) - 3'], {
     strokeWidth: 3,
     strokeColor: JXG.palette.red,
     strokeOpacity: 0.8
 });

var niveauline = [];
niveauline = [0.5, 1, 1.5, 2];
for (let i = 0; i < niveauline.length; i++) {
    board.create("implicitcurve", [
        (x, y) => x ** .5 * y ** .5 - niveauline[i],
           [0.25, 3], [0.5, 4] // Domain
    ], {
        strokeWidth: 2,
        strokeColor: JXG.palette.red,
        strokeOpacity: (1 + i) / niveauline.length,
        needsRegularUpdate: false
    });
}

Attributes

Own

alpha_0

Description: Angle α₀ between two successive tangents: determines the smoothness of the curve.
Type: Number | function
Default Value: 0.05
Source: options.js, line 6236

delta_0

Description: Allowed distance (in user units) of predictor point to curve.
Type: Number | function
Default Value: 0.05
Source: options.js, line 6308

h_critical

Description: If h is below this threshold (in user units), we bail out of the tracing phase of that component.
Type: Number | function
Default Value: 0.001
Source: options.js, line 6328

h_initial

Description: Initial step width (in user units).
Type: Number | function
Default Value: 0.1
Source: options.js, line 6318

h_max

Description: Maximum step width (in user units).
Type: Number | function
Default Value: 0.5
Source: options.js, line 6339

kappa_0

Description: Inverse of desired number of Newton steps.
Type: Number | function
Default Value: 0.2
Source: options.js, line 6298

loop_detection

Description: Use Gosper's loop detector.
Type: Boolean | function
Default Value: true
Source: options.js, line 6369

loop_dir

Description: Minimum acos of angle to detect loop.
Type: Number | function
Default Value: 0.99
Source: options.js, line 6359

loop_dist

Description: Allowed distance (in user units multiplied by actual step width) to detect loop.
Type: Number | function
Default Value: 0.09
Source: options.js, line 6349

margin

Description: Defines the margin (in user coordinates) around the JSXGraph board in which the implicit curve is plotted.
Type: Number | function
Default Value: 1
Source: options.js, line 6191

max_steps

Description: Maximum iterations for one component of the implicit curve.
Type: Number | function
Default Value: 1024
Source: options.js, line 6226

qdt_box

Description: Half of the box size (in user units) to search for existing line segments in the quadtree.
Type: Number | function
Default Value: 0.2
Source: options.js, line 6288

resolution_inner

Description: Vertical resolution (in pixel) to search for components of the implicit curve. A small number increases the running time. For large number components may be missed. Minimum value is 0.01.
Type: Number | function
Default Value: 5
Source: options.js, line 6214

resolution_outer

Description: Horizontal resolution: distance (in pixel) between vertical lines to search for components of the implicit curve. A small number increases the running time. For large number components may be missed. Minimum value is 0.01.
Type: Number | function
Default Value: 5
Source: options.js, line 6202

tol_0

Description: Tolerance to find starting points for the tracing phase of a component.
Type: Number | function
Default Value: JXG.Math.eps
Source: options.js, line 6247

tol_cusp

Description: Tolerance for cusp / bifurcation detection.
Type: Number | function
Default Value: 0.05
Source: options.js, line 6267

tol_newton

Description: Tolerance for the Newton steps.
Type: Number | function
Default Value: 1.0e-7
Source: options.js, line 6257

tol_progress

Description: If two points are closer than this value, we bail out of the tracing phase for that component.
Type: Number | function
Default Value: 0.0001
Source: options.js, line 6277

Inherited

gradientSecondOpacity

highlightStrokeOpacity

highlightStrokeWidth

ignoreForLabelAutoposition

Members

Own

domain

Description: Defines a domain for searching f(x,y)=0. Default is null, meaning the bounding box of the board is used. Using domain, visProp.margin is ignored.
Source: base/curve.js, line 3605