RMagick 2.9.0: RVG Reference: Transforms

###### RMagick 2.9.0 User's Guide and Reference

# The transform methods

## About the transform methods

The default coordinate system has its origin in the upper-left corner. The positive x-axis extends to the right. The positive y-axis extends downward. You can change this coordinate system by using one or more of the transform methods described on this page. This image shows the default coordinate system.

This image shows a drawing without transformations.

The transform methods are defined in the RVG, RVG::Group, and RVG::Use classes. You can also chain these methods to the shape methods and to the image method.

## Transform methods

#### matrix

obj.matrix(sx, rx, ry, sy, tx, ty) -> obj

##### Description

Replaces the current transformation matrix with a new matrix having the specified values. See the SVG standard for more information.

##### Arguments

sx, sy
  The scale factor in the x-dimension and y-dimension, measured in user coordinates.
rx, ry
  The amount of rotation about the x-axis and y-axis, measured in degrees.
tx, ty
  The translation on the x-axis and the y-axis, measured in user coordinates.

#### rotate

obj.rotate(angle[, cx, cy]) -> obj

##### Description

Rotates the axes about the origin or, if cx and cy are present, about the specified point.

##### Arguments

angle
  The amount of rotation. Positive angles rotate clockwise, negative angles rotate counter-clockwise.
cx, cy
  If present, the point to rotate about.

##### Example

See scale.

#### scale

obj.scale(sx[, sy]) -> obj

##### Description

Scales the axes.

##### Arguments

sx
  The amount of scaling on the x-axis.
sy
  If present, the amount of scaling on the y-axis. Otherwise defaults to sx.

##### Example

#### skewX

obj.skewX(angle) -> obj

##### Description

Skews the x-axis.

##### Arguments

angle
  The skew amount, measured in degrees.

##### Example

See skewY

#### skewY

obj.skewY(angle) -> obj

##### Description

Skews the y-axis.

##### Arguments

angle
  The skew amount, measured in degrees.

##### Example

#### translate

obj.translate(tx[, ty]) -> obj

##### Description

Moves the origin.

##### Arguments

tx
  The location of the new origin on the x-axis.
ty
  The location of the new origin on the y-axis. If omitted, defaults to tx.

##### Example