Whoops. Hit "send" too quickly. Jason Turner wrote: > tol <- sqrt(.Machine$double.eps) > dcrn[(fn - inve[2]) < tol] that should be dcrn[abs(fn - inve[2]) < tol] -- Indigo Industrial Controls Ltd. http://www.indigoindustrial.co.nz 64-21-343-545 jasont at indigoindustrial.co.nz