Compute the covariance or correlation between (the corresponding pixel values in) several images.
cov.im(..., use = "everything", method = c("pearson", "kendall", "spearman"))A symmetric matrix.
Any number of arguments, each of which is
a pixel image (object of class "im").
Alternatively, a single argument which is a list of pixel images.
Argument passed to cov
or cor determining how to handle
NA values in the data.
Argument passed to cov
or cor determining the type of correlation
that will be computed.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.
The arguments ...
should be pixel images (objects of class "im").
Their spatial domains must overlap, but need not have the same
pixel dimensions.
These functions compute the covariance or correlation between the corresponding pixel values in the images given.
The pixel image domains are intersected, and converted to a common pixel resolution. Then the corresponding pixel values of each image are extracted. Finally the correlation or covariance between the pixel values of each pair of images, at corresponding pixels, is computed.
The result is a symmetric matrix with one row and column for each image.
The [i,j] entry is the correlation or covariance between
the ith and jth images in the argument list.
The row names and column names of the matrix are copied from the
argument names if they were given (i.e. if the arguments were given
as name=value).
Note that cor and cov
are not generic, so you have to type cor.im, cov.im.