@spiceErrorCheck<EOL>def lgrind(xvals, yvals, x):
n = ctypes.c_int(len(xvals))<EOL>xvals = stypes.toDoubleVector(xvals)<EOL>yvals = stypes.toDoubleVector(yvals)<EOL>work  = stypes.emptyDoubleVector(n.value*<NUM_LIT:2>)<EOL>x  = ctypes.c_double(x)<EOL>p  = ctypes.c_double(<NUM_LIT:0>)<EOL>dp = ctypes.c_double(<NUM_LIT:0>)<EOL>libspice.lgrind_c(n, xvals, yvals, work, x, p, dp)<EOL>return p.value, dp.value<EOL>
Evaluate a Lagrange interpolating polynomial for a specified
set of coordinate pairs, at a specified abscissa value.
Return the value of both polynomial and derivative.

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

:param xvals: Abscissa values.
:type xvals: N-Element Array of floats
:param yvals: Ordinate values.
:type yvals: N-Element Array of floats
:param x: Point at which to interpolate the polynomial.
:type x: float
:return: Polynomial value at x, Polynomial derivative at x.
:rtype: tuple