@spiceErrorCheck<EOL>def trace(matrix):
matrix = stypes.toDoubleMatrix(matrix)<EOL>return libspice.trace_c(matrix)<EOL>
Return the trace of a 3x3 matrix.

http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/trace_c.html

:param matrix: 3x3 matrix of double precision numbers.
:type matrix: 3x3-Element Array of floats
:return: The trace of matrix.
:rtype: float