Convert Pixel Image from Numeric to Factor
Transform the values of a pixel image from numeric values into a factor.
## S3 method for class 'im' cut(x, ...)
x |
A pixel image.
An object of class |
... |
Arguments passed to |
This simple function applies the generic cut
operation
to the pixel values of the image x
. The range of pixel values
is divided into several intervals, and each
interval is associated with a level of a factor.
The result is another pixel image,
with the same window and pixel grid as
x
, but with the numeric value of each pixel discretised
by replacing it by the factor level.
This function is a convenient way to inspect an image and to obtain summary statistics. See the examples.
To select a subset of an image, use the subset operator
[.im
instead.
A pixel image (object of class "im"
) with
pixel values that are a factor.
See im.object
.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au
and Rolf Turner r.turner@auckland.ac.nz
# artificial image data Z <- setcov(square(1)) Y <- cut(Z, 3) Y <- cut(Z, breaks=seq(0,1,length=5)) # cut at the quartiles # (divides the image into 4 equal areas) Y <- cut(Z, quantile(Z))
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