scalardilate
Apply Scalar Dilation
Applies scalar dilation to a plane geometrical object, such as a point pattern or a window, relative to a specified origin.
Usage
scalardilate(X, f, ...) ## S3 method for class 'im':
scalardilate(X, f, \dots, origin=NULL)
## S3 method for class 'owin':
scalardilate(X, f, \dots, origin=NULL)
## S3 method for class 'ppp':
scalardilate(X, f, \dots, origin=NULL)
## S3 method for class 'psp':
scalardilate(X, f, \dots, origin=NULL)
## S3 method for class 'default':
scalardilate(X, f, \dots)
Arguments
- X
- Any suitable dataset representing a two-dimensional
object, such as a point pattern (object of class
"ppp"
), a window (object of class"owin"
), a pixel image (class"im"
) and so on. - f
- Scalar dilation factor. A finite number greater than zero.
- ...
- Ignored by the methods.
- origin
- Origin for the scalar dilation. Either a vector of 2 numbers,
or one of the character strings
"centroid"
,"midpoint"
or"bottomleft"
(partially matched).
Details
This command performs scalar dilation of the object X
by the factor f
relative to the origin specified by
origin
.
The function scalardilate
is generic, with methods for
windows (class "owin"
), point patterns (class "ppp"
),
pixel images (class "im"
), line segment patterns (class "psp"
)
and a default method.
If the argument origin
is not given,
then every spatial coordinate is multiplied by the factor f
.
If origin
is given, then scalar dilation is performed
relative to the specified origin. Effectively, X
is shifted
so that origin
is moved to c(0,0)
, then scalar dilation
is performed, then the result is shifted so that c(0,0)
is
moved to origin
.
This command is a special case of an affine transformation:
see affine
.
Value
- Another object of the same type, representing the result of applying the scalar dilation.
See Also
Examples
plot(letterR)
plot(scalardilate(letterR, 0.7, origin="bot"), col="red", add=TRUE)