euler: Euler
In Tokazama/iClass: More intuitive syntax for manipulating imaging data

Description Usage Arguments Value Author(s) References See Also Examples

Calculates the euler characteristic at a threshold level

1	euler(u, df, fieldType)

`u`	Statistical value (typically the maxima of a cluster or statistical field).
`df`	Degrees of freedom expressed as c(degrees of interest, degrees of error).
`fieldType:`	'T'T-field 'F'F-field 'X'Chi-square field' 'Z'Gaussian field

A vector of estimated euler characteristics for dimensions 0:D.

Zachary P. Christensen

Worlsey K.J., (1996) A Unified Statistical Approach for Determining Significant Signals in Images of Cerebral Activation.

rftPval, resels

## generate some data as if we just fitted a linear regression
outimg1 <- makeImage(c(10,10,10), rt(1000))
maskimg <- getMask(outimg1)
fwhm <- estSmooth(outimg1, maskimg)
resels <- resels(maskimg, fwhm$fwhm)
ec <- euler(max(outimg1), c(1,10), fieldType='T')
pvox <- sum(ec*resels)