Vector.Log2 Method

Overload List

#	Signature	Description
1	function Log2: TMtxVec;	Log base 2.
	└ indexed: function Log2(Index: Integer; Len: Integer): TMtxVec;
2	function Log2(const X: TMtxVec): TMtxVec;	Calculate the log base 2 for all X elements.
	└ indexed: function Log2(const X: TMtxVec; XIndex: Integer; Index: Integer; Len: Integer): TMtxVec;

Overload 1: function Log2: TMtxVec;

Log base 2.

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

Remarks:

Calculate the log base 2 for all calling object elements in-place.

Examples

var a,b: Vector;
begin
    a.SetIt(False,[1,2,4,8]);
    a.Log2;  //same as:
    a := Log2(a);
    b := Log2(a); //same as:
    b.Log2(a);
end;

var
    a, expected: Vector;
begin
    a := [1.0, 2.0, 4.0, 10.0];
    a.Log2;
    expected := [0.0, 1.0, 2.0, 3.32192809488736];
    if not a.IsEqual(expected, 1e-10, TCompare.cmpAbsolute) then
        raise Exception.Create('Vector.Log2: mismatch');
end;

See Also: Vector.Exp2

Indexed: function Log2(Index: Integer; Len: Integer): TMtxVec;

Calculate the log base 2 for 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 Vector.ConditionCheck is True and array borders are overrun.

Overload 2: function Log2(const X: TMtxVec): TMtxVec;

Calculate the log base 2 for all X elements.

#	Name	Type	Description
1	X	TMtxVec

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

Remarks:

Store the results in the calling object. Size and Vector.Complex properties of the calling vector are set implicitly to match the X object.

Examples

var
    a, x, expected: Vector;
begin
    x := [1.0, 2.0, 4.0, 10.0];
    a.Log2(x);
    expected := [0.0, 1.0, 2.0, 3.32192809488736];
    if not a.IsEqual(expected, 1e-10, TCompare.cmpAbsolute) then
        raise Exception.Create('Vector.Log2: mismatch');
end;

Indexed: function Log2(const X: TMtxVec; XIndex: Integer; Index: Integer; Len: Integer): TMtxVec;

Calculate the log base 2 for X elements [XIndex]..[XIndex+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:

Store the results in the calling object elements [Index]..[Index+Len-1]. Size and Vector.Complex properties of the calling object must be set explicitly. An exception is raised if Vector.ConditionCheck is True and array borders are overrun.