# quaternion QML Value Type

A quaternion type has scalar, x, y, and z attributes. More...

## Detailed Description

A `quaternion` type has `scalar`, `x`, `y` and `z` attributes.

To create a `quaternion` value, specify it as a "scalar,x,y,z" string, or define the components individually, or compose it with the Qt.quaternion() function.

The quaternion type has the following idempotent functions which can be invoked in QML:

Function SignatureDescriptionExample
real dotProduct(quaternion other)Returns the scalar real result of the dot product of `this` quaternion with the `other` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = Qt.quaternion(5,6,7,8);
var c = a.dotProduct(b);
console.log(c); // 70```
quaternion times(quaternion other)Returns the quaternion result of multiplying `this` quaternion with the `other` quaternion, which corresponds to applying both of the rotations
```var a = Qt.quaternion(1 / Math.sqrt(2), 1 / Math.sqrt(2), 0, 0);
var b = Qt.quaternion(1 / Math.sqrt(2), 0, 1 / Math.sqrt(2), 0);
var c = b.times(a);
console.log(c.toString()); // QQuaternion(0.5, 0.5, 0.5, -0.5)```
vector3d times(vector3d vector)Returns the vector3d result of rotating the `vector` with `this` quaternion
```var a = Qt.quaternion(0.5,0.5,0.5,-0.5);
var b = Qt.vector3d(4,5,6);
var c = a.times(b);
console.log(c.toString()); // QVector3D(5, -6, -4)```
quaternion times(real factor)Returns the quaternion result of multiplying `this` quaternion with the scalar `factor`
```var a = Qt.quaternion(1,2,3,4);
var b = 4.48;
var c = a.times(b);
console.log(c.toString()); // QQuaternion(4.48, 8.96, 13.44, 17.92)```
quaternion plus(quaternion other)Returns the quaternion result of the addition of `this` quaternion with the `other` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = Qt.quaternion(5,6,7,8);
var c = a.plus(b);
console.log(c.toString()); // QQuaternion(6, 8, 10, 12)```
quaternion minus(quaternion other)Returns the quaternion result of the subtraction of `other` quaternion from `this` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = Qt.quaternion(5,6,7,8);
var c = a.minus(b);
console.log(c.toString()); // QQuaternion(-4, -4, -4, -4)```
quaternion normalized()Returns the normalized unit form of `this` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = a.normalized();
console.log(b.toString()); // QQuaternion(0.182574, 0.365148, 0.547723, 0.730297)```
quaternion inverted()Returns the inverse of `this` quaternion
```var a = Qt.quaternion(0.5,0.5,0.5,-0.5);
var b = a.inverted();
console.log(b.toString()); // QQuaternion(0.5, -0.5, -0.5, 0.5)```
quaternion conjugated()Returns the conjugate of `this` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = a.conjugated()
console.log(b.toString()); // QQuaternion(1, -2, -3, -4)```
real length()Returns the scalar real value of the length of `this` quaternion
```var a = Qt.quaternion(1,2,3,4);
var b = a.length();
console.log(b.toString()); // 5.477225575051661```
vector3d toEulerAngles()Returns the vector3d Euler angles (in degrees) that corresponds to `this` quaternion
```var a = Qt.quaternion(0.933012,0.25,-0.25,0.066987);
var b = a.toEulerAngles();
console.log(b.toString()); // QVector3D(30, -30, -4.28846e-05)```
vector4d toVector4d()Returns the vector4d result of converting `this` quaternion to a vector4d
```var a = Qt.quaternion(1,2,3,4);
var b = a.toVector4d();
console.log(b.toString()); // QVector4D(2, 3, 4, 1)```
bool fuzzyEquals(quaternion other, real epsilon)Returns true if `this` quaternion is approximately equal to the `other` quaternion. The approximation will be true if each attribute of `this` is within `epsilon` of `other`. Note that `epsilon` is an optional argument, the default `epsilon` is 0.00001.
```var a = Qt.quaternion(1,2,3,4);
var b = Qt.quaternion(1.0001, 1.9998, 2.0001, 3.9999);
var c = a.fuzzyEquals(b);        // default epsilon
var d = a.fuzzyEquals(b, 0.005); // supplied epsilon
console.log(c + " " + d); // false true```

Properties of type `quaternion` have `Qt.quaternion(1, 0, 0, 0)` as their default value.

This value type is provided by the QtQuick import.