pub unsafe extern "C" fn gr_interp2(
nx: c_int,
ny: c_int,
x: *const f64,
y: *const f64,
z: *const f64,
nxq: c_int,
nyq: c_int,
xq: *const f64,
yq: *const f64,
zq: *mut f64,
method: interp2_method_t,
extrapval: f64,
)