CLI_diff

diff

Compute signed differences per variable and cell: file2 - file1. file1 is the baseline and file2 is the comparison. Negative results are preserved; this is not the absolute value of the difference.

nes diff -1 baseline.nc -2 comparison.nc -o difference.nc -l NO2 O3

Argument	Meaning
-1	Required baseline file
-2	Required comparison file
-o, --output_file	Required output file
-l, --var_list	Optional variable list; defaults to shared data variables

Variables explicitly selected must exist in both files. Shapes must match. The implementation checks shapes, but does not align coordinates or convert units: use inputs with matching grids, timestamps, levels and units.