B-splines
Have also a look at "Cubic spline interpolation".
The points in this example are connected by a cubic B-spline curve (i.e. order=4).
<button onClick="addSegment();">Add random segment</button>
<button onClick="removeSegment();">Remove last segment</button>
// Define the id of your board in BOARDID
const board = JXG.JSXGraph.initBoard(BOARDID, {
boundingbox: [-4, 4, 4, -4],
keepaspectratio: true,
axis: true
});
var p = [],
col = 'red';
// Create initial 7 points
p.push(board.create('point', [2, 1], {color: col}));
p.push(board.create('point', [0.75, 2.5], {color: col}));
p.push(board.create('point', [-0.3, 0.3], {color: col}));
p.push(board.create('point', [-3, 1], {color: col}));
p.push(board.create('point', [-0.75, -2.5], {color: col}));
p.push(board.create('point', [1.5, -2.8], {color: col}));
p.push(board.create('point', [2, -0.5], {color: col}));
// Create B-spline curve
var c = board.create('curve', JXG.Math.Numerics.bspline(p, 4), {
strokecolor: 'blue', strokeOpacity: 0.6, strokeWidth: 5});
var addSegment = function() {
p.push(board.create('point', [Math.random() * 8 - 4, Math.random() * 8 - 4], {
strokeColor: col,
fillColor: col
}));
board.update();
};
var removeSegment = function() {
if (p.length > 2) {
board.removeObject(p[p.length - 1]); // remove the last point from the list of objects
p.splice(p.length - 1, 1); // remove the last point from the point array.
board.update();
}
};
This example is licensed under a Creative Commons Attribution 4.0 International License.
Please note that you have to mention The Center of Mobile Learning with Digital Technology in the credits.