validity of an eddy depending not only on its amplitude but also its
surface. (Note that, in this version, the component valid is redundant: one
can simply test the component out_cont%n_points.)

define a selection of extrema. Then get their coordinates. This
prepares the way for a more complex selection: taking cylonicity into account.

procedure get_snapshot. The idea is that, in this branch, nearby_extr
will eventually include extrema depending not only on them having
sufficient amplitude but also on their cyclonicity. Both pieces of
information cannot be simply encoded in extr_map. The downside is that
we compute needlessly nearby_extr if e%radius4 == 1 in set_max_speed.

read_snapshot, assert that there is no duplicate tuple in
s%ind_extr. Since we are not sure of that, we must use a do construct
and not a forall in order to define s%extr_map.

Bug fix in program test_local_extrema: support missing values. Add
corresponding test.

Output s%ind_extr in program test_read_snapshot.

init_shapefiles. This allows us to have variables for DBF field
numbers, as module variables. We avoid the burden of passing this
large number of variables as arguments to write_eddy. Safer to have
variables for DBF field numbers than relying on the order of those
fields.

Remove file_list. This was a duplication of information.

Use named constant for missing max speed value. It is used in two procedures.

to 1e4, safer too.

instead of defining the component ssh to the ssh of the extremum or to
the ssh of the outermost contour, use a missing value flag
(1e4). Also, when radius4 >= 2 and the max speed contour is the
outermost contour, use missing value flag in the ssh component of max
speed contour instead of ssh on outermost contour. This makes clearer
output.

Add function null_ssh_contour.

In procedure get_1_outerm, simplify the comparison of level_try and
level_good. So we do not need any longer the dummy argument
ssh_extremum.

of local variable radius in procedure set_max_speed. Add corresponding
column in outermost_contour DBF file. This is just a diagnostic of the
workings of get_snapshot. Clearer to have this output than having
special meaning in components ssh and area of speed_cont.

to out_cont and speed_cont (shorter names).

For ssh, missing value is huge(0.). We have to take a large value
because Contour_531 has an argument zmax for missing values. For
velocity, missing value is a quiet NaN. We have to take this because
we need to know if the interpolation procedure in mean_speed has not
used any missing value and we do not want to alter the interpolation
procedure itself.

In local_extrema, we accept as local extrema only points with 8 valid
values around them.

When we look for the maximum speed contour, we are hoping that good
contours do not englobe missing values. If this happens, the program
aborts.

When computing the mean speed on a contour, we are hoping that the
interpolation of speed on contour points does not use missing
values. If this happens, the program aborts.

Draw coastlines in plot_snaphot.py. At the same time, this allows the
use of any projection.

set_all_outerm. Thus, we have the clearer intent(out) for argument s
of set_all_outerm. Also, this prepares a possible replacement of
set_all_outerm by a procedure from the Topology toolkit.

Create test program for procedure set_all_outerm.

set_all_outerm, for clarity.

program behavior.

In plot_snapshot.py, no need to accumulate all content of shapefile
extremum_1, just process it record by record, as for other shapefiles.

out-of-range index so add min when calculating urc.

Bug fix in procedure good_contour. polygon_contains_point should not
be called if polyline is not closed.

Procedure polygon_contains_point became unpure so remove pure for
procedure inside_4 too.

In program test_good_contour, read corner and step from namelist
rather than from coordinates in NetCDF file. Makes it possible to use
the same NetCDF file with different coordinates. Also read
outside_points from a file rather than standard input so there is no
need to specify in advance the number of outside points.

Take into account the possibility that no outermost contour was found
in program test_set_outermost_contour. Also, use fixed names for input
files because it is not convenient to require a particular order of
these two files on the command line.

contour no longer means that the eddy is interpolated.

acceptable. So define flat_extr by a strict inequality in procedure
get_snapshot.

Procedure set_outermost_contour no longer has a dummy argument
noise_around. We no longer call outermost_possible_level so we do not
have an artificial discontinuity of results with and without maximum
amplitude. We abandon the idea of reducing the amplitude of initial
level_good compared to innermost_level: problem of consistence with
get_snapshot, and it does not seem worth the trouble, just abandon
those problematic extrema. Allow for null outermost_contour instead of
aborting.

In procedure get_snapshot, s%list_vis(i)%suff_amp is first defined
only if flat_extr(i). Also we are no longer sure that
set_outermost_contour finds an outermost contour so we have to test
this to define s%list_vis(i)%suff_amp. noise_around is now defined
only for flat_extr(i) and s%list_vis(i)%suff_amp. Also, since we may
not find an outermost contour even if not flat_extr(i), we update
s%extr_map after the second call to set_outermost_contour.

In procedure local_extrema, we use the mask diff_center instead of
mask_center. So we no longer need procedure construct_mask_center. In
procedure local_extrema, we ignore one in two adjacent degenerate
extrema instead of aborting.

In plot_snapshot.py, color extrema and allow for null outermost
contour.

Synthesize output in test_local_extrema.py.

Make program test_good_contour more general.

low-amplitude threshold, min_amp.

Add component suff_amp to derived type eddy. Write this component in
extremum_$m.dbf.

In shapefiles, write positions of vertices in degrees rather than
radians.

test_get_snapshot reads the whole domain of input NetCDF files instead
of selecting a window through a namelist. This is clearer and more
convenient. Same in test_get_snapshot.py, test_local_extrema and
test_local_extrema.py.

In test_get_snapshot.py, annotate extrema instead of inserting a
legend.

More correct names: radian_per_degree to deg_over_rad,
degree_per_radian to rad_over_deg.

local_extrema instead of coding sense of rotation with the sign of
extr_map.

In makefile, we want tags to include sources for test_good_contour,
etc. External file list becomes easier.

Moved test_bilinear_interp.f and test_bilinear_interp.py out of the
project. These are rather tests on Numer_Rec_95.

In test_local_extrema, write to CSV file instead of stdout.