JXG.Curve

Ft(t) → {Array}

Return the homogeneous coordinates of the curve at t - including all transformations applied to the curve.

Parameters

Returns

Type

Array

Details

Source

base/curve.js, line 239

X(t, suspendUpdate) → {Number}

The parametric function which defines the x-coordinate of the curve.

Parameters

Returns

Type

Number

Details

Source

base/curve.js, line 207

Y(t, suspendUpdate) → {Number}

The parametric function which defines the y-coordinate of the curve.

Parameters

Returns

Type

Number

Details

Source

base/curve.js, line 220

Z(t) → {Number}

Treat the curve as curve with homogeneous coordinates.

Parameters

Returns

Type

Number

Details

Source

base/curve.js, line 229

addTransform(transform) → {JXG.Curve}

Add transformations to this curve.

Parameters

Returns

Type

JXG.Curve

Details

Overrides

JXG.GeometryElement#addTransform

Source

base/curve.js, line 921

allocatePoints()

Allocate points in the Coords array this.points

Details

Source

base/curve.js, line 409

generateTerm(varname, xterm, yterm, miopt, maopt)

Converts the JavaScript/JessieCode/GEONExT syntax of the defining function term into JavaScript. New methods X() and Y() for the Curve object are generated, further new methods for minX() and maxX(). If mi or ma are not supplied, default functions are set.

Parameters

Details

See

• JXG.GeonextParser.geonext2JS

Source

base/curve.js, line 1050

getCoords() → {Array}

Return the points of the curve as array of length-three-arrays [z, x, y], i.e. return an array of homogeneous coordinates. The returned coordinates are in user coordinates. Finite homogeneous coordinates have the first value set to 1, i.e. it can be ignored.

The points of the curve are either the elements of the properties dataX and dataY or the result of the plotting algorithm. In any case, the points are stored in the private property "points".

Returns

Type

Array

Details

Source

base/curve.js, line 1498

getLabelPosition(pos, distance) → {JXG.Coords}

Position a curve label according to the attributes "position" and distance. This function is also used for angle, arc and sector.

Parameters

Returns

Type

JXG.Coords

Details

Source

base/curve.js, line 1171

(private) getTransformationSource() → {Array}

If the curve is the result of a transformation applied to a continuous curve, the glider projection has to be done on the original curve. Otherwise there will be problems when changing between high and low precision plotting, since there number of points changes.

Returns

Type

Array

Details

Source

base/curve.js, line 1473

hasPoint(x, y, start) → {Boolean}

Checks whether (x,y) is near the curve.

Parameters

Returns

Type

Boolean

Details

Overrides

JXG.GeometryElement#hasPoint

Source

base/curve.js, line 260

(private) interpolationFunctionFromArray(which) → {function}

Generate the method curve.X() in case curve.dataX is an array and generate the method curve.Y() in case curve.dataY is an array.

Parameters

Returns

Type

function

Details

Source

base/curve.js, line 958

maxX() → {Number}

Gives the default value of the right bound for the curve. May be overwritten in JXG.Curve#generateTerm.

Returns

Type

Number

Details

Source

base/curve.js, line 182

minX() → {Number}

Gives the default value of the left bound for the curve. May be overwritten in JXG.Curve#generateTerm.

Returns

Type

Number

Details

Source

base/curve.js, line 161

moveTo(where) → {JXG.Curve}

Shift the curve by the vector 'where'.

Parameters

Returns

Type

JXG.Curve

Details

Source

base/curve.js, line 1441

notifyParents(contentStr)

Finds dependencies in a given term and notifies the parents by adding the dependent object to the found objects child elements.

Parameters

Details

Source

base/curve.js, line 1135

update() → {JXG.Curve}

Generates points of the curve to be plotted.

Returns

Type

JXG.Curve

Details

Overrides

JXG.GeometryElement#update

See

• JXG.Curve#updateCurve

Source

base/curve.js, line 431

updateCurve() → {JXG.Curve}

Computes the curve path

Returns

Type

JXG.Curve

Details

See

• JXG.Curve#update

Source

base/curve.js, line 749

updateDataArray()

For dynamic dataplots updateCurve can be used to compute new entries for the arrays JXG.Curve#dataX and JXG.Curve#dataY. It is used in JXG.Curve#updateCurve. Default is an empty method, can be overwritten by the user.

Examples

// This example overwrites the updateDataArray method.
// There, new values for the arrays JXG.Curve.dataX and JXG.Curve.dataY
// are computed from the value of the slider N

var N = board.create('slider', [[0,1.5],[3,1.5],[1,3,40]], {name:'n',snapWidth:1});
var circ = board.create('circle',[[4,-1.5],1],{strokeWidth:1, strokecolor:'black', strokeWidth:2,
		fillColor:'#0055ff13'});

var c = board.create('curve', [[0],[0]],{strokecolor:'red', strokeWidth:2});
c.updateDataArray = function() {
        var r = 1, n = Math.floor(N.Value()),
            x = [0], y = [0],
            phi = Math.PI/n,
            h = r*Math.cos(phi),
            s = r*Math.sin(phi),
            i, j,
            px = 0, py = 0, sgn = 1,
            d = 16,
            dt = phi/d,
            pt;

        for (i = 0; i < n; i++) {
            for (j = -d; j <= d; j++) {
                pt = dt*j;
                x.push(px + r*Math.sin(pt));
                y.push(sgn*r*Math.cos(pt) - (sgn-1)*h*0.5);
            }
            px += s;
            sgn *= (-1);
        }
        x.push((n - 1)*s);
        y.push(h + (sgn - 1)*h*0.5);
        this.dataX = x;
        this.dataY = y;
    }

var c2 = board.create('curve', [[0],[0]],{strokecolor:'red', strokeWidth:1});
c2.updateDataArray = function() {
        var r = 1, n = Math.floor(N.Value()),
            px = circ.midpoint.X(), py = circ.midpoint.Y(),
            x = [px], y = [py],
            phi = Math.PI/n,
            s = r*Math.sin(phi),
            i, j,
            d = 16,
            dt = phi/d,
            pt = Math.PI*0.5+phi;

        for (i = 0; i < n; i++) {
            for (j= -d; j <= d; j++) {
                x.push(px + r*Math.cos(pt));
                y.push(py + r*Math.sin(pt));
                pt -= dt;
            }
            x.push(px);
            y.push(py);
            pt += dt;
        }
        this.dataX = x;
        this.dataY = y;
    }
    board.update();

// This is an example which overwrites updateDataArray and produces
// a Bezier curve of degree three.
var A = board.create('point', [-3,3]);
var B = board.create('point', [3,-2]);
var line = board.create('segment', [A,B]);

var height = 0.5; // height of the curly brace

// Curly brace
var crl = board.create('curve', [[0],[0]], {strokeWidth:1, strokeColor:'black'});
crl.bezierDegree = 3;
crl.updateDataArray = function() {
    var d = [B.X()-A.X(), B.Y()-A.Y()],
        dl = Math.sqrt(d[0]*d[0]+d[1]*d[1]),
        mid = [(A.X()+B.X())*0.5, (A.Y()+B.Y())*0.5];

    d[0] *= height/dl;
    d[1] *= height/dl;

    this.dataX = [ A.X(), A.X()-d[1], mid[0], mid[0]-d[1], mid[0], B.X()-d[1], B.X() ];
    this.dataY = [ A.Y(), A.Y()+d[0], mid[1], mid[1]+d[0], mid[1], B.Y()+d[0], B.Y() ];
};

// Text
var txt = board.create('text', [
                    function() {
                        var d = [B.X()-A.X(), B.Y()-A.Y()],
                            dl = Math.sqrt(d[0]*d[0]+d[1]*d[1]),
                            mid = (A.X()+B.X())*0.5;

                        d[1] *= height/dl;
                        return mid-d[1]+0.1;
                    },
                    function() {
                        var d = [B.X()-A.X(), B.Y()-A.Y()],
                            dl = Math.sqrt(d[0]*d[0]+d[1]*d[1]),
                            mid = (A.Y()+B.Y())*0.5;

                        d[0] *= height/dl;
                        return mid+d[0]+0.1;
                    },
                    function() { return "length=" + JXG.toFixed(B.Dist(A), 2); }
                ]);


board.update(); // This update is necessary to call updateDataArray the first time.

Details

Source

base/curve.js, line 740

updateRenderer() → {JXG.Curve}

Updates the visual contents of the curve.

Returns

Type

JXG.Curve

Details

Overrides

JXG.GeometryElement#updateRenderer

Source

base/curve.js, line 446

updateTransform(p) → {JXG.Point}

Applies the transformations of the curve to the given point p. Before using it, JXG.Curve#updateTransformMatrix has to be called.

Parameters

Returns

Type

JXG.Point

Details

Source

base/curve.js, line 904