def get_grid_points(user_axis, crs_axis):
"""
Computes the number of grid points corresponding to the axis.
:param UserAxis user_axis: the axis as given by the user
:param CrsAxis crs_axis: the corresponding crs axis
:return: int gridPoints
"""
# if no interval on the axis (slice), then 1 single grid point
if user_axis.interval.high is None:
return 1
if isinstance(user_axis, RegularUserAxis):
# number of geo-intervals over resolution
if user_axis.type != UserAxisType.DATE:
# number_of_grid_points = (geo_max - geo_min) / resolution
grid_points = abs(
(decimal.Decimal(str(user_axis.interval.high)) -
decimal.Decimal(str(user_axis.interval.low))) /
decimal.Decimal(str(user_axis.resolution)))
# The resolution in ingredient file can have big factor to the calculation, so must take care
if abs(
decimal.Decimal(str(grid_points), ROUND_UP) -
grid_points) > HighPixelAjuster.THRESHOLD:
log.warning(
"The computed number of grid points is not an integer for axis "
+ user_axis.name +
". This usually indicates that the resolution is not correct."
)
grid_points = HighPixelAjuster.adjust_high(grid_points)
# Negative axis (e.g: latitude) min <--- max
if user_axis.resolution < 0:
return int(math.floor(grid_points))
else:
# Positive axis (e.g: longitude) min ---> max
return int(math.ceil(grid_points))
else:
time_difference = user_axis.interval.high - user_axis.interval.low
# AS time always point to future (min --> max)
if crs_axis.is_time_day_axis():
# days ((seconds / 86400) / resolution)
grid_points = abs(
(decimal.Decimal(str(time_difference)) /
decimal.Decimal(DateTimeUtil.DAY_IN_SECONDS)) /
decimal.Decimal(str(user_axis.resolution)))
grid_points = HighPixelAjuster.adjust_high(grid_points)
return int(math.ceil(grid_points))
else:
# seconds (seconds / resolution)
grid_points = abs(
(decimal.Decimal(str(time_difference)) /
decimal.Decimal(str(user_axis.resolution))))
grid_points = HighPixelAjuster.adjust_high(grid_points)
return int(math.ceil(grid_points))
else:
# number of direct positions (i.e: irregular axis with coefficients [0, 1, 3, 5, 8, 15])
return len(user_axis.directPositions)
def get_origin(user_axis, crs_axis):
"""
Computes the origin for the user_axis by shifting the limit with half resolution.
:param UserAxis user_axis: the axis as given by the user.
:return: float origin
"""
# if axis is datetime then just return the low
if user_axis.type == UserAxisType.DATE:
return PointPixelAdjuster.get_origin_for_time_axis(
user_axis, crs_axis)
if isinstance(user_axis, RegularUserAxis):
if user_axis.resolution > 0 or user_axis.interval.high is None:
# axis goes from low to high, so origin is lowest, with half a pixel shift
# min (min + 0.5*resolution) --> max
return decimal.Decimal(str(user_axis.interval.low))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution))
else:
# axis goes from high to low, so origin is highest, with half pixel shift (resolution is negative)
# min <---- (max + 0.5*resolution) max
return decimal.Decimal(str(user_axis.interval.high))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution))
else:
# irregular axis, the same but without shift
# normally, irregular axis points from min ---> max, so origin is min (e.g: time ansidate, unixtime)
if user_axis.resolution > 0 or user_axis.interval.high is None:
return user_axis.interval.low
else:
return user_axis.interval.high
def adjust_axis_bounds_to_continuous_space(user_axis, crs_axis):
"""
Moves pixels inside the user_axis from the middle of the interval to the bounds of the interval.
:param UserAxis user_axis: the axis given by the user
:param crs_axis is the axis from SECORE (e.g: 4326, Ansidate, UnixTime)
:return: None
"""
if user_axis.type == UserAxisType.DATE:
PointPixelAdjuster.adjust_axis_bounds_for_time_axis(user_axis, crs_axis)
else:
# if low < high, adjust it
if user_axis.interval.high is not None and user_axis.interval.low > user_axis.interval.high:
user_axis.interval.low, user_axis.interval.high = user_axis.interval.high, user_axis.interval.low
if isinstance(user_axis, RegularUserAxis):
user_axis.interval.low = decimal.Decimal(str(user_axis.interval.low)) \
- decimal.Decimal(str(0.5)) * abs(decimal.Decimal(str(user_axis.resolution)))
if user_axis.interval.high:
user_axis.interval.high = decimal.Decimal(str(user_axis.interval.high)) \
+ decimal.Decimal(str(0.5)) * abs(decimal.Decimal(str(user_axis.resolution)))
def adjust_axis_bounds_for_time_axis(user_axis, crs_axis):
# convert to timestamp and change the axis type
user_axis.interval.low = arrow.get(
user_axis.interval.low).float_timestamp
if user_axis.interval.high:
user_axis.interval.high = arrow.get(
user_axis.interval.high).float_timestamp
# if low < high, adjust it
if user_axis.interval.high is not None and user_axis.interval.low > user_axis.interval.high:
user_axis.interval.low, user_axis.interval.high = user_axis.interval.high, user_axis.interval.low
# The formula for all regular axes is when "pixelIsPoint":
# min = min - 0.5 * resolution
# max = max + 0.5 * resolution
if isinstance(user_axis, RegularUserAxis):
# if axis is time axis
if crs_axis.is_time_day_axis():
user_axis.interval.low = decimal.Decimal(str(user_axis.interval.low)) \
- decimal.Decimal(0.5) * decimal.Decimal(str(abs(user_axis.resolution))) * DateTimeUtil.DAY_IN_SECONDS
if user_axis.interval.high:
user_axis.interval.high = decimal.Decimal(str(user_axis.interval.high)) \
+ decimal.Decimal(0.5) * decimal.Decimal(str(abs(user_axis.resolution))) * DateTimeUtil.DAY_IN_SECONDS
else:
# if axis is normal axis (lat, lon, index1d,...)
user_axis.interval.low = decimal.Decimal(str(user_axis.interval.low)) \
- decimal.Decimal(0.5) * decimal.Decimal(str(abs(user_axis.resolution)))
if user_axis.interval.high:
user_axis.interval.high = decimal.Decimal(str(user_axis.interval.high)) \
+ decimal.Decimal(0.5) * decimal.Decimal(str(abs(user_axis.resolution)))
def get_origin_for_time_axis(user_axis, crs_axis):
user_axis.interval.low = arrow.get(
user_axis.interval.low).float_timestamp
if user_axis.interval.high:
user_axis.interval.high = arrow.get(
user_axis.interval.high).float_timestamp
if isinstance(user_axis, RegularUserAxis):
# ansidate, need to calculate with day in seconds
if crs_axis.is_time_day_axis:
if user_axis.resolution > 0 or user_axis.interval.high is None:
# axis goes from low to high, so origin is lowest, with half a pixel shift
return decimal.Decimal(str(user_axis.interval.low))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution)) * DateTimeUtil.DAY_IN_SECONDS
else:
# axis goes from high to low, so origin is highest, with half pixel shift (resolution is negative)
return decimal.Decimal(str(user_axis.interval.high))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution)) * DateTimeUtil.DAY_IN_SECONDS
else:
# unix time, already in seconds
if user_axis.resolution > 0 or user_axis.interval.high is None:
# axis goes from low to high, so origin is lowest, with half a pixel shift
return decimal.Decimal(str(user_axis.interval.low))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution))
else:
# axis goes from high to low, so origin is highest, with half pixel shift (resolution is negative)
return decimal.Decimal(str(user_axis.interval.high))\
+ decimal.Decimal(0.5) * decimal.Decimal(str(user_axis.resolution))
else:
# irregular axis, the same but without shift
if user_axis.resolution > 0 or user_axis.interval.high is None:
return user_axis.interval.low
else:
return user_axis.interval.high