def _make_partially_collapsed_coord(self, coord, grid, guessed_axis):
"""
Make a new DimCoord which represents a partially collapsed (aggregated into bins) coordinate.
This dimcoord will have a grid
:type coord: data_io.Coord.Coord
:param coord: Coordinate to partially collapse
:type grid: aggregation.aggregation_grid.AggregationGrid
:param grid: grid on which this coordinate will aggregate
:type guessed_axis: str
:param guessed_axis: String identifier of the axis to which this coordinate belongs (e.g. 'T', 'X')
:return: DimCoord
"""
if grid.is_time or guessed_axis == 'T':
# Ensure that the limits are date/times.
dt = parse_datetime.convert_datetime_components_to_datetime(grid.start, True)
grid_start = Subset._convert_datetime_to_coord_unit(coord, dt)
dt = parse_datetime.convert_datetime_components_to_datetime(grid.end, False)
grid_end = Subset._convert_datetime_to_coord_unit(coord, dt)
grid_delta = grid.delta
else:
# Assume to be a non-time axis
(grid_start, grid_end) = Subset._fix_non_circular_limits(float(grid.start), float(grid.end))
grid_delta = float(grid.delta)
new_coordinate_grid = aggregation_grid_array(grid_start, grid_end, grid_delta, grid.is_time, coord)
new_coord = DimCoord(new_coordinate_grid, var_name=coord.name(), standard_name=coord.standard_name,
units=coord.units)
if len(new_coord.points) == 1:
new_coord.bounds = [[grid_start, grid_end]]
else:
new_coord.guess_bounds()
return new_coord
def aggregation_grid_array(start, end, delta, is_time, coordinate):
if is_time:
start_dt = Subset._convert_coord_unit_to_datetime(coordinate, start)
end_dt = Subset._convert_coord_unit_to_datetime(coordinate, end)
# Some logic to find the mid point to start on
if delta.year > 0:
start_dt = add_year_midpoint(start_dt, delta.year)
# We make an assumption here that half a month is always 15 days.
if delta.month > 0:
start_dt = add_month_midpoint(start_dt, delta.month)
dt = datetime.timedelta(days=delta.day, seconds=delta.second, microseconds=0, milliseconds=0,
minutes=delta.minute, hours=delta.hour, weeks=0)
start_dt += dt / 2
new_time_grid = []
new_time = start_dt
while new_time < end_dt:
new_time_grid.append(Subset._convert_datetime_to_coord_unit(coordinate, new_time))
new_year = new_time.year + delta.year
new_month = new_time.month + delta.month
if new_month > 12:
new_month, new_year = month_past_end_of_year(new_month, new_year)
# TODO this is a slightly inelegant fix for the problem of something like 30th Jan +1 month
# Need to work out what correct behaviour should be in this case.
try:
new_time = new_time.replace(year=new_year, month=new_month)
except ValueError:
new_time += datetime.timedelta(days=28)
new_time += datetime.timedelta(days=delta.day, seconds=delta.second, microseconds=0, milliseconds=0,
minutes=delta.minute, hours=delta.hour, weeks=0)
new_time_grid = numpy.array(new_time_grid)
return new_time_grid
else:
new_grid = numpy.arange(start + delta / 2, end + delta / 2, delta)
return new_grid
