@spiceErrorCheck<EOL>def pltexp(iverts, delta):
iverts = stypes.toDoubleMatrix(iverts)<EOL>delta = ctypes.c_double(delta)<EOL>overts = stypes.emptyDoubleMatrix()<EOL>libspice.pltexp_c(iverts, delta, overts)<EOL>return stypes.cMatrixToNumpy(overts)<EOL>
Expand a triangular plate by a specified amount. The expanded 
plate is co-planar with, and has the same orientation as, the 
original. The centroids of the two plates coincide. 

https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/pltexp_c.html

:param iverts: Vertices of the plate to be expanded. 
:type iverts: 3x3-Element Array of floats
:param delta: Fraction by which the plate is to be expanded.
:type delta: double
:return: Vertices of the expanded plate. 
:rtype: 3x3-Element Array of floats