Developer and experimental codes for FINUFFT
--------------------------------------------

For generating kernel coefficient codes in ../src,
the developer must run from MATLAB the following:

gen_all_horner_C_code.m        : writes C-style Horner coeffs (pre-2024)
  * a single call writes upsampfac=2 and 1.25
  * calls gen_ker_horner_loop_C_code.m
gen_all_horner_cpp_header.m    : writes C++ header Horner coeffs (July 2024 on)
  * a single call writes upsampfac=2 and 1.25
  * calls gen_ker_horner_loop_cpp_code.m

Both of the gen_ker_* scripts call for the solve of the coeffs for each w:
ker_ppval_coeff_mat.m
  (which has the kernel definition in it, which must match spreadinterp.cpp)

The universal location for kernel approximation (degree, ES beta setting) is:
get_degree_and_beta.m
Tweaks should be done here, and see instructions there for resulting acc test.
Another code that has to match ../src/spreadinterp.cpp is:
reverse_engineer_tol.m

Re measuring overall accuracy, to compare kernels, make matlab, and run:
matlab/test/fig_accuracy.m

Barnett 8/20/24
