In script `eddy_dump.py`, do not assume that there is a single date
index. So find ishape by iterating through values of date index and
eddy index.

Add a test of overlap in `short_tests.json`.

In procedure `write_eddy`, no need of special treatment for
interpolated eddy: the outermost contours and max-speed contours are
defined as null.

Read name of input file on the command line in script `read_overlap.py`.

Add tests with program `test_overlap` in `short_tests.json`.

Bug fix in main unit `test_overlap`: we have to call
`init_interpolated_eddy`.  In main unit `test_overlap`, change the
initial value of `flow(2:max_delta)%number_eddies` for more clarity in
the results. Bug fix in main unit `test_overlap`: valid isolated
eddies of snasphot 2 are in `flow(max_delta + 1)`, not `flow(2)`.

Rename `test_successive_overlap` to `test_overlap`: we will also use
it for non-successive overlap. Accordingly, add an input variable
`max_delta` and change the size of flow to `max_delta` + 1. We read
from snapshots `flow(1)` and `flow(max_delta + 1)`. For
`flow(2:max_delta)`, we only need to define the component
`number_eddies`.

In tests, remove use of `$test_old_dir`, use data from
`$src_dir/Tests/Input` instead. Motivation: run tests for the first
time more easily.

Change the order of dummy arguments of `write_overlap`.

Add tests for program `test_write_overlap`. In program
`test_write_overlap`, make the eddy identifiers distinct.

Create procedure `init_interpolated_eddy` so that initialization is
not repeated needlessly at each call of `write_overlap`. (Problem was
mentioned in message of commit 10f339d2.)

Use `SHP_triplet` instead of Snapshot for the name of the directory
containing the three shapefiles extremum, `outermost_contour` and
`max_speed_contour`. This is meant as a general name, analogous to a
new file type. Generally, the shapefiles may contain eddies at
different dates, not just a snapshot.

Add options for the NAG compiler.

Replace `target_include_directories` by `include_directories` in
`Tests/CMakeLists.txt`. The file was becoming too long.

Remove unused items in use statements.

Bug fix in `Tests/Input/successive_overlap_region_5_nml.txt`: remove a comma.

Bug fix in procedure overlap: procedure `interpolate_eddy` does not
exist any longer.

In tests, remove use of `$test_old_dir`, use data from
`$src_dir/Tests/Input` instead. Motivation: run tests for the first
time more easily.

Change order of dummy arguments of procedure
`write_overlap`. Motivation: call with keywords in
`test_write_overlap`.

Add main program `test_write_overlap` and corresponding tests in
`short_tests.json`.

New script `triplet_dump.sh`.

Add `.cmake` files. The idea is to have a build system independent of
the environment. This allows us to have a customized version of
`ConfigureCompilerFlags.cmake` without the `-ffpe-trap=invalid`
option.

Move the inner part of procedure overlap to a separate procedure
`write_overlap`. overlap was too complex with 6 nested constructs. The
downside is that the initialization of `e` is repeated for every
non-successive overlap. If necessary, we can later add an
initialization on first entry (but an initialization at declaration is
not possible). `write_overlap` has some consistency: all the arguments
are `intent(in)`, scalars or small vectors of intrinsic type, and
`write_overlap` only writes to files. All modifications to flow are
done outside of `write_overlap`.

Remove procedure `interpolate_eddy`. I realized that the longitude of
one of the overlapping eddies must be shifted. It seemed awkward to
pass variable m from overlap as an argument to
`interpolate_eddy`. Passing separately the useful components of
overlapping eddies made the procedure bulky, not worth creating for
three lines of computation.

As a consequence, inline the interpolation of eddies in procedure
overlap. An advantage is that part of the processing that was in
`interpolate_eddy` can migrate out of the interpolation loop.

As another consequence, remove program `test_interpolate_eddy` and
correponding test.

Upgrade procedure `candidate_overlap` to deal with non-successive
overlap. Add dummy argument delta.

Make the program `test_interpolate_eddy` more comfortable to use by
reading a directory on the command line.

Create main program `test_interpolate_eddy`. Add corresponding test in
`short_tests.json`. Add corresponding input files.

Move dummy arguments k and i of procedure `write_eddy` to the end of
dummy argument list: keyword association more likely for these.

Follow upgrade of `Shapelib_03`: move argument associated to dummy
argument hshp of `shp_open_03` to the beginning of argument list.

Use `dbf_read_attribute_03` instead of dbfreadattribute in procedure
`read_eddy`. This also allows us to avoid the intermediary real
`c_double` variable. Modify intent of hshp arguments, taking also
advantage of upgrade of `shp_read_object_03` in `Shapelib_03`.

Create general script `mkdir_run.sh` to replace specific
scripts `extraction_eddies.sh`, `test_read_snapshot.sh`,
`test_read_eddy.sh` and to run `test_successive_overlap`.

Replace `$input_dir` by `$src_dir/Tests/Input` in
`*_tests.json`. Motivation: we also need `src_dir` to point to
`mkdir_run.sh`.

Replace `intent(inout)` by `intent(in)` for shpfileobject arguments in
`write_eddy`. This requires an updated version of `Shapelib_03`.

Changing my mind, `interpolate_eddy` only interpolates, it does not
write the interpolated eddy, this seems clearer. So it can be a
function instead of a subroutine and we call `write_eddy` from
overlap. We need to add arguments `hshp_extremum`, `hshp_outermost`
and `hshp_max_speed` to overlap. The main program
`test_successive_overlap` now has to create shapefiles.

Prepare for overlap of eddies at non-successive dates:

- add argument `delta_out` to procedure `candidate_overlap` (not yet
used);
- add procedure `interpolate_eddy` (empty for now);
- rename `successive_overlap` to overlap because the procedure will handle both
cases, successive dates and non-successive dates;
- generalize procedure overlap to handle delta between dates.

for which `delta_out` == 1 and eddies for which `delta_in` == 1. This
is redundant with information in file `edgelist.csv`. I have checked
in test `Successive_overlap_global` that eddies for which `delta_out`
== 1 correspond to column i1 (sorted, unique) and eddies for which
`delta_in` == 1 correspond to column i2 (sorted, unique).

Take into account new policy in `filter.py`: the names of the three
shapefiles are always the same and form a unit in a snaphot directory.

Rename `compil_prod_dir`to `build_dir` in JSON test files. Add a test
of `successive_overlap` with global grid, normal resolution.

Take into account new policy in `filter.py`: the names of the three
shapefiles are always the same and form a unit in a snaphot directory.

Rename `compil_prod_dir`to `build_dir` in JSON test files. Add a test
of `successive_overlap` with global grid, normal resolution.

`test_successive_overlap`.

`settings.mk` in GNUmakefile.

Bug fix in procedure `dispatch_snapshot`: an isolated eddy is a valid eddy.

In script `plot_snapshot.py`, in function snaphot, replace argument ax
with argument `new_figure` so the user does not have to call figure
and `axes(projection = projection)`. Add argument light to function
snapshot so we can call snapshot with light set to False for a second
snapshot. Add a test to only read `h.nc` when we need it.

In script `read_overlap.py`, print more information: number of nodes,
number of edges, number of nodes with at least one successor, number
of nodes with at least one predecessor, splitting events, merging
events.

In script `stat.py`, use the convention that shapefiles are grouped in
a directory instead of identifying a set of shapefiles by the end of
their basename.

In main program `test_successive_overlap`, we know that `delta_in` for
snapshot 1 and `delta_out` for snapshot 2 are `huge(0)` so do not test
this. Print eddy identifiers in a single line. Add the printing of
identifiers of isolated eddies.

splitting and merging.

`snapshot`. Also, move calls to `ax.gridlines` and `ax.coastlines`
inside function `snapshot`. These changes allow us to call `snapshot`
in a new figure.

Move `Region4/2006_01_01` to `Region4_2006_01_01` and
`Region4/2006_01_02` to `Region4_2006_01_02`.

Add a test of `successive_overlap` for a larger region, for which the
identifying numbers of the connected eddies are not the same for all
edges. Add corresponding input files.

Bug fix in main program `test_successive_overlap`.

snapshots in the same figure: useful for visualizing overlaps. So move
lines plotting a snapshot inside a new function called
snapshot and add option `--dashed`.

Remove the option `-e` of `plot_snaphot.py` and add directory argument
instead. The idea is that we now consider the three shapefiles as a
whole, they should always be alone in a dedicated directory.

Move the three shapefiles of `Tests/Input/Region_4/2006_01_02` to a
dedicated directory.

In `plot_snapshot.py`, netCDF variables for wind are now expected to be
called ugos and vgos.

Add a test for overlap of two different snapshots.

files, that make up a snapshot into a directory that contains only
these files. We hope that this will ease the handling of
snapshots. For now, this is useful in program
test_successive_overlap. So, in program extraction_eddies, create the
shapefiles in a directory called Snapshot. As we cannot create the
directory from Fortran (in Fortran 2003, it becomes possible in
Fortran 2008), we have to wrap the Fortran executable in a shell
script "extraction_eddies.sh". In the same way, read from a directory
Snapshot_old in programs test_read_eddy and test_read_snapshot and
create scripts "test_read_eddy.sh" and "test_read_snapshot.sh".

Reference the shell scripts "extraction_eddies.sh",
"test_read_eddy.sh" and "test_read_snapshot.sh" in JSON test files.

In program test_successive_overlap, finally read two snapshots, from
directories Snapshot_1 and Snapshot_2. Pass to successive_overlap the
date of the second snapshot. Use new variables corner_deg and step_deg
to avoid converting to rad twice.

Create directory Snapshot in Tests/Input/Region_4/2006_01_01.

overlap, we will have to read a set of three shapefiles, extremum,
outermost_contour and max_speed_contour, containing several
snapshots. We do not want to re-read field indices for each snapshot.

Rename u, v to ugos, vgos in NetCDF files.

vgos, lon to longitude, lat to latitude.

Add a test for successive_overlap with periodic grid.

Add snapshot for region 4 at a different date, in input files, for a
new test of successive_overlap.

read_snapshot and successive_overlap instead of a named constant of
module successive_overlap_m.

Bug fix in main programs test_read_snapshot and
test_successive_overlap: take into account that step is in degrees.

not sure about this. I will stay on the safe side for now.

Support periodic grid in successive_overlap.

eddies at date "j" in a new function candidate_overlap. This reduces
the number of nested constructs from 8 to 5. Incidentally, we can now
avoid defining needlessly polyline_1 if there is no candidate at date
"j". Also the function candidate_overlap should also be called by
non_successive_overlap.

Add argument periodic to procedure successive_overlap.

In main unit test_successive_overlap, pass to successive_overlap the
date subscript returned by read_snapshot instead of an arbitrary
value. Only print delta_in and delta_out if they are /= huge.