"Fseval" = function(tpscoeff, coords1, target)
{
	#thin-plate spline defined on coords1, evaluated on target
	#
	if(mode(coords1) == "complex") c1 <- coords1 else {
		c1a <- coords1
		c1 <- complex(real = c1a[, 1], imag = c1a[, 2])
	}
	if(mode(target) == "complex")
		t1 <- target
	else {
		t1a <- target
		t1 <- complex(real = t1a[, 1], imag = t1a[, 2])
	}
	nland <- length(c1)
	ntarg <- length(t1)
	affine <- array(tpscoeff[nland + 1.], ntarg) + tpscoeff[nland + 2.] * Re(t1) + tpscoeff[nland + 3.] * Im(t1)
	kernels <- array(t1, c(ntarg, nland))
	centers <- aperm(array(c1, c(nland, ntarg)), c(2., 1.))
	sepmtx <- kernels - centers
	terms <- Re(sepmtx * Conj(sepmtx))
	terms <- ifelse(terms > 0., 0.5 * terms * log(terms), 0.)
	coeffs <- aperm(array(tpscoeff[1.:nland], c(nland, ntarg)), c(2., 1.))
	partials <- terms * coeffs
	nonaff <- apply(partials, 1., sum)
	dtarget <- affine + nonaff
	dtarget <- cbind(Re(dtarget), Im(dtarget))
	return(list(affine = affine, nonaff = nonaff, dtarget = dtarget))
}