<!--Copyright (C) 1988-2005 by the Institute of Global Environment and Society (IGES). See file COPYRIGHT for more information.--> <h2><b>tan </b></h2><p> <code>tan(<i>expr</i>)</code><p> Applies the trigonometric tangent function to the <code><i>expr</i></code> which is assumed to be in radians. Operates on both gridded and station data. <H3>Usage Notes</H3><P> <H3>Examples</H3><P>