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# QVector2D Class Reference[QtGui module]

The QVector2D class represents a vector or vertex in 2D space. More...

### Special Methods

• QVector2D __add__ (self, QVector2D v2)
• QVector2D __div__ (self, float divisor)
• bool __eq__ (self, QVector2D v2)
• QVector2D __iadd__ (self, QVector2D vector)
• QVector2D __idiv__ (self, float divisor)
• QVector2D __imul__ (self, float factor)
• QVector2D __imul__ (self, QVector2D vector)
• QVector2D __isub__ (self, QVector2D vector)
• QVector2D __mul__ (self, QVector2D vector)
• QVector2D __mul__ (self, float factor)
• QVector2D __mul__ (self, QVector2D v2)
• bool __ne__ (self, QVector2D v2)
• QVector2D __neg__ (self)
• str __repr__ (self)
• QVector2D __sub__ (self, QVector2D v2)

## Detailed Description

This class can be pickled.

The QVector2D class represents a vector or vertex in 2D space.

The QVector2D class can also be used to represent vertices in 2D space. We therefore do not need to provide a separate vertex class.

Note: By design values in the QVector2D instance are stored as float. This means that on platforms where the qreal arguments to QVector2D functions are represented by double values, it is possible to lose precision.

## Method Documentation

### QVector2D.__init__ (self)

Constructs a null vector, i.e. with coordinates (0, 0, 0).

### QVector2D.__init__ (self, float xpos, float ypos)

Constructs a vector with coordinates (xpos, ypos).

### QVector2D.__init__ (self, QPointpoint)

Constructs a vector with x and y coordinates from a 2D point.

### QVector2D.__init__ (self, QPointFpoint)

Constructs a vector with x and y coordinates from a 2D point.

### QVector2D.__init__ (self, QVector3Dvector)

Constructs a vector with x and y coordinates from a 3D vector. The z coordinate of vector is dropped.

### QVector2D.__init__ (self, QVector4Dvector)

Constructs a vector with x and y coordinates from a 3D vector. The z and w coordinates of vector are dropped.

### float QVector2D.dotProduct (QVector2Dv1, QVector2Dv2)

Returns the dot product of v1 and v2.

### bool QVector2D.isNull (self)

Returns true if the x and y coordinates are set to 0.0, otherwise returns false.

### float QVector2D.length (self)

Returns the length of the vector from the origin.

### float QVector2D.lengthSquared (self)

Returns the squared length of the vector from the origin. This is equivalent to the dot product of the vector with itself.

### QVector2D.normalize (self)

Normalizes the currect vector in place. Nothing happens if this vector is a null vector or the length of the vector is very close to 1.

### QVector2D QVector2D.normalized (self)

Returns the normalized unit vector form of this vector.

If this vector is null, then a null vector is returned. If the length of the vector is very close to 1, then the vector will be returned as-is. Otherwise the normalized form of the vector of length 1 will be returned.

### QVector2D.setX (self, float aX)

Sets the x coordinate of this point to the given x coordinate.

### QVector2D.setY (self, float aY)

Sets the y coordinate of this point to the given y coordinate.

### QPoint QVector2D.toPoint (self)

Returns the QPoint form of this 2D vector.

### QPointF QVector2D.toPointF (self)

Returns the QPointF form of this 2D vector.

### QVector3D QVector2D.toVector3D (self)

Returns the 3D form of this 2D vector, with the z coordinate set to zero.

### QVector4D QVector2D.toVector4D (self)

Returns the 4D form of this 2D vector, with the z and w coordinates set to zero.

### float QVector2D.x (self)

Returns the x coordinate of this point.

### float QVector2D.y (self)

Returns the y coordinate of this point.

### QVector2D QVector2D.__sub__ (self, QVector2Dv2)

 PyQt 4.9.4 for Windows Copyright © Riverbank Computing Ltd and Nokia 2012 Qt 4.8.2