<h3>transform function</h3>
Returns the geometry transformed from the source CRS to the dest CRS.

<h4>Syntax</h4>
<pre>transform( geom, sAuthId, dAuthId )</pre>

<h4>Arguments</h4>
geom &rarr; QgsGeometry

sCrsId &rarr; the Source Auth CRS Id

dCrsId &rarr; the Dest Auth CRS Id

<h4>Example</h4>
<pre> geomToWKT( transform( $geometry, 'EPSG:2154', 'EPSG:4326' ) ) &rarr; POINT(0 51)</pre>
