Mathematical functions

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Revision as of 19:10, 30 January 2009 by A WASSERMANN (talk | contribs)

Functions of the JavaScript Object Math

The following functions are part of every JavaScript virtual machine:

  • Math.abs;
  • Math.acos;
  • Math.asin;
  • Math.atan;
  • Math.ceil;
  • Math.cos;
  • Math.exp;
  • Math.floor;
  • Math.log;
  • Math.max;
  • Math.min;
  • Math.random;
  • Math.sin;
  • Math.sqrt;
  • Math.tan;

JSXGraph expands the set of available mathematical functions. To keep the JavaScript implementations clean, the new mathematical functions are part of the JSXGraph board. That means, initially a board has to be created, for example with the command

board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 40, unitY: 40});

Then, the object board contains the following additional mathematical functions:

  • board.angle(A, B, C): for Point objects A, B, C. (A: name string, id string or object pointer)
  • board.rad(A, B, C)
  • board.distance(arr1, arr2): Euclidean distane between two vectors
  • board.pow(a, b): [math]\displaystyle{ a^b }[/math] for floating point value of b. Math.pow is defined for integer values of b', only.
  • board.round(x, n): returns string with fixed point representation of x. It is aa wrapper for string.tofixed(n).
  • board.cosh(x)
  • board.sinh(x)
  • board.D(f): Numerically computed derivative of the function f, returns a function.
  • board.I(interval,f): Numerically computed v alue integral of the function f in the given interval.
  • board.root(f,x): root of the function f. Uses Newton method with start value x.
  • board.factorial(n): computes [math]\displaystyle{ n! = n\cdot(n-1)\cdots2\cdot 1 }[/math].
  • board.lagrangePolynomial(p): returns a function which describes the Lagrange polynomial through the points in the array p.