Matrix.ArcCos Method

Overload List

#	Signature	Description
1	function ArcCos: TMtxVec;	The inverse cosine.
	└ indexed: function ArcCos(Index: Integer; Len: Integer): TMtxVec;
2	function ArcCos(const X: TMtxVec): TMtxVec;	Calculate the inverse cosine of all X object elements and store the results in the calling object.
	└ indexed: function ArcCos(const X: TMtxVec; XIndex: Integer; Index: Integer; Len: Integer): TMtxVec;

Overload 1: function ArcCos: TMtxVec;

The inverse cosine.

Result: stored in self (calling object), returns self for chaining

Remarks:

Calculate the inverse cosine of all calling object elements in-place. Values must be between -1 and 1. The return values will be in the range [0,PI], in radians.

Examples

var a,b: Matrix;
begin
    a.SetIt(1,2 True,[1,-0.5,0.11,0.9]);
    a.ArcCos;  // or
    b := ArcCos(a); // or
    a := ArcCos(a);
end;

var
    a, expected: Matrix;
begin
    a := [[0.0, 0.5], [0.707106781186548, 0.866025403784439]];
    a.ArcCos;
    expected := [[1.5707963267949, 1.0471975511966], [0.785398163397448, 0.523598775598299]];
    if not a.IsEqual(expected, 1e-10, TCompare.cmpAbsolute) then
        raise Exception.Create('Matrix.ArcCos: mismatch');
end;

See Also: Matrix.Cos

Indexed: function ArcCos(Index: Integer; Len: Integer): TMtxVec;

Calculate the inverse cosine of calling object elements [Index]...[Index+Len-1] in-place.

#	Name	Type	Description
1	Index	Integer	start index
2	Len	Integer	element count

Result: stored in self (calling object), returns self for chaining

Remarks:

An exception is raised if array borders are overrun.

Overload 2: function ArcCos(const X: TMtxVec): TMtxVec;

Calculate the inverse cosine of all X object elements and store the results in the calling object.

#	Name	Type	Description
1	X	TMtxVec

Result: stored in self (calling object), returns self for chaining

Remarks:

Size and Matrix.Complex properties of calling object are adjusted automatically.

Examples

var
    a, x, expected: Matrix;
begin
    x := [[0.0, 0.5], [0.707106781186548, 0.866025403784439]];
    a.ArcCos(x);
    expected := [[1.5707963267949, 1.0471975511966], [0.785398163397448, 0.523598775598299]];
    if not a.IsEqual(expected, 1e-10, TCompare.cmpAbsolute) then
        raise Exception.Create('Matrix.ArcCos: mismatch');
end;

Indexed: function ArcCos(const X: TMtxVec; XIndex: Integer; Index: Integer; Len: Integer): TMtxVec;

Calculate the inverse cosine of X object elements [XIndex]...[XIndex+Len-1]. The results are stored in calling object elements [Index]...[Index+Len-1].

#	Name	Type	Description
1	X	TMtxVec
2	XIndex	Integer	X start index
3	Index	Integer	start index
4	Len	Integer	element count

Result: stored in self (calling object), returns self for chaining

Remarks:

Size and Matrix.Complex properties of the calling object must be set explicitly. An exception is raised if array borders are overrun.