It is `min_area` that we need in the code, in `get_1_outerm`. Instead
of computing it in the main program and trickling it down to
`get_1_outerm`, define it in `config_m`.

Create function `plot_grid_points` from code which was in the "script
portion" of the module. This new function could be useful when
importing the module for interactive work. Also, creating this
function clarifies the module.

This must be the case, since commit f7c5ec74.

This is the same as the number of extrema, since commit f7c5ec74.

It can never happen.

We need it to open `e_overestim.txt`. unit was undefined for `i_slice
/=  - 1`. The bug came from commit af5da9e8.

copy was undefined. The bug came from commit 7f24341b.

Read path to the pre-existing `cont_list` shapefile on the command line.

Because we are going to use it for another path.

It is a little simpler to use `cont_list_m` and we then have the speed
in `cont_list.dbf`. The pre-existing `cont_list` shapefile is now open
for read access only.

No more preprocessor directive in the file.

This is not very useful, now that there is the test on
`write_cont_list`. The test on `write_cont_list` should not be a
performance penalty.

Since we now have speed in the shapefile `cont_list`.

Move output of `cont_list` from `set_contours` to `set_max_speed`. The
advantage is that we will be able to add the speed to the shapefile.

`null_ssh_contour` is not used since commit e0a05ba6.

We rewrite `inst_eddies_Aviso.py` so it is more convenient to use. The
script is only useful for several input files. Otherwise we can
directly use `inst_eddies.py`. So instead of optional arguments
template and last date, we use positional arguments. Then there is no
point in distinguishing dirname and basename. Also, it does not make
sense any longer to read the date from the content of the first
file. The script becomes more general: we do not assume that all input
NetCDF files are in the same -directory and that the time coordinate
is in days since 1950-1-1. The interface is also clearer.

We need ssh of extremum in `set_contours`, to compute `innermost_level_2`.

Because we are going to use it for another field.

Instead of standard output.

Since it is not in the shapefiles.

Remove option `--dashed` of script `plot_eddy_contours.py`. This
option was added in commit 5e0e0deb. The dummy argument dashed of
function snapshot is useful because we can call snapshot several times
on the same axes from elsewhere, but I do not see how the option
`--dashed` of script `plot_eddy_contours.py` is useful, since we
create a new figure when we run the script.

Check that `SHPC_dir` exists at initialization of instance of class
SHPC. Before this commit, if `SHPC_dir` did not exist, there was an
error trying to create `n_slices.txt`, which was less clear.

Add the possibility to write `cont_list` from `set_contours`. We want
to do that without impacting the main program unit `inst_eddies`. We
do not want to centralize variables at hight level in
`inst_eddies`. So we do not want to promote `cont_list` and `n_cont`
to dummy arguments of `set_contours`.