floating point exception in diffusion calibration

[travissluka]

On S4:

The test_soca_parameters_diffusion_hz test is reporting divide by zero floating point exceptions`:

ExplicitDiffusion: Initializing grid
    dx:   min=   120334.934974120      max=   555445.468565858      mean=   393656.163455253
    dy:   min=   178373.694756197      max=   556572.393098238      mean=   546009.328135308
    area: min=   37224097758.6346      max=   308715610406.179      mean=   217037061598.128
Info     : Direct calibration
ExplicitDiffusion: running calibration
 group  1 of  2
  name: hz_large
  horizontal calibration:
    Reading length scales from file
    input values as gaussian (vs GC half width):  F
    L_hz: min=   1.4E+06  max=   5.2E+06  mean=   3.2E+06


Floating point exception detected: Divide by zero

Floating point exception detected: Divide by zero

 0# 0x00002B271E625DB0 in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/liboops.so
 1# 0x00002B27277BB630 in /lib64/libpthread.so.0
 2# soca_diffusion_mod_mp_soca_diffusion_calibrate_hz_ in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/libsoca.so
 3# soca_diffusion_mod_mp_soca_diffusion_calibrate_ in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/libsoca.so
 4# soca_explicitdiffusion_calibrate_f90 in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/libsoca.so
 5# soca::ExplicitDiffusion::directCalibration(oops::FieldSets const&) in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/libsoca.so
 6# 0x00000000004CF148 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
 7# 0x00000000004E5DB0 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
 8# 0x000000000050D302 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
 9# 0x000000000051F912 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
10# 0x0000000000525524 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
11# 0x00000000004B9AA6 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
12# 0x00000000005248A7 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
13# oops::Run::execute(oops::Application const&, eckit::mpi::Comm const&) in /data/users/sherbener/projects/jedi-bundle/build/bin/../lib64/liboops.so
14# 0x000000000042EF4D in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x
15# __libc_start_main in /lib64/libc.so.6
16# 0x000000000042ECA9 in /data/users/sherbener/projects/jedi-bundle/build/bin/soca_error_covariance_toolbox.x

Originally posted by @srherbener in https://github.com/JCSDA-internal/jedi-bundle/issues/78#issuecomment-1879367206

[travissluka]

closing. All that code was rewritten so not sure if its still a problem