GeoEco.Datasets.Virtual.ClippedGrid

class GeoEco.Datasets.Virtual.ClippedGrid(grid, clipBy='Cell indices', xMin=None, xMax=None, yMin=None, yMax=None, zMin=None, zMax=None, tMin=None, tMax=None)

Bases: Grid

A Grid that trims a Grid to a smaller spatiotemporal extent.

Parameters:

• grid (Grid) – Grid to clip.

• clipBy (str, optional) –

  Specifies the type of extent values that will be used to clip the grid, one of:

  • Map coordinates - the values are coordinates in space and time. Typically this means that x and y coordinates will be in degrees (if a geographic coordinate system is used) or a linear unit such as meters (if a projected coordinate system is used), the z (depth) coordinate will be in a linear unit such as meters, and the t (time) coordinate will be a date and time string in a standard format such as YYYY-MM-DD HH:MM:SS, or a Python datetime instance.

  • Indices - the values are integer indices of cells in the grid, starting at 0 and ending at the maximum index value. For example, if a 2D grid has 360 columns and 180 rows, the x and y indices will range from 0 to 359 and 0 to 179, respectively.

  If Indices is specified but floating point numbers are provided for the extent values, the decimal portions of the numbers will be truncated (e.g. the value 1.7 will be truncated to 1).

  If Map coordinates is specified and a coordinate value falls within a cell, rather than exactly on a boundary between two cells, the cell will be included in the clipped grid (it will not be clipped out). Because computers cannot represent all floating-point numbers at full precision, the resulting rounding errors can sometimes produce unexpected results. For example, consider a grid with a cell size of 0.1. We expect that the cells centered at 0.5 and 1.5 would meet at coordinate value 0.1, but 0.1 cannot be fully represented by the computer using standard 64-bit floating-point numbers. The computer rounds it to 0.10000000000000001. Therefore, if you were to clip the grid a maximum coordinate of 0.10000000000000001, you would expect that the cell centered at 1.5 would be included in the resulting grid, because 0.10000000000000001 falls within that cell. But the computer actually considers the boundary between the two cells to be at 0.10000000000000001, not 0.1, so that cell would be clipped out.

  Allowed values꞉ 'Map coordinates', 'Cell indices'.

• xMin (float, optional) – Minimum x coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the negative x direction.

• xMax (float, optional) – Maximum x coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the positive x direction.

• yMin (float, optional) – Minimum y coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the negative y direction.

• yMax (float, optional) – Maximum y coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the positive y direction.

• zMin (float, optional) – Minimum z coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the negative z direction.

• zMax (float, optional) – Maximum z coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be an integer or a floating point number. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the positive z direction.

• tMin (object, optional) – Minimum t coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be a date and time string in a standard format such as YYYY-MM-DD HH:MM:SS or a Python datetime instance. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the negative t direction.

• tMax (object, optional) – Maximum t coordinate or index. The Clip By parameter determines whether the value is a coordinate or an index. If a coordinate is provided, it may be a date and time string in a standard format such as YYYY-MM-DD HH:MM:SS or a Python datetime instance. If an index is provided, it must be an non-negative integer. If a value is not provided, the clipped grid will extend to the full extent in the positive t direction.

Returns:

ClippedGrid instance.

Return type:

ClippedGrid

Properties

property CenterCoords

(object) Coordinates of the grid cell centers, indexed using the 1-character dimension of interest and optionally a range to retrieve a numpy.ndarray of coordinates (e.g. CenterCoords['x', 0:4]) or an integer to retrieve a float for a single coordinate (e.g. CenterCoords['x', 10]). Coordinates for the t dimension are returned as datetime instances. Read only.

property CoordDependencies

(tuple of str) Same length as Dimensions. Dimensions that each dimension depends on for determining its coordinates. None for dimensions that have a constant coordinate increment. Read only.

property CoordIncrements

(tuple of float) Same length as Dimensions. Coordinate increment for each dimension. None for dimensions that do not have a constant coordinate increment. Read only.

property Data

(object) This grid’s data, indexable using slices (e.g. grid.Data[:, 5:10, -10:]) or integers (e.g. grid.Data[0,1,-2]) or both in combination. Strides and negative indexes are supported in the traditional manner. If the grid is writable, Data can be assigned to write values to the grid, e.g. grid.Data[0,1] = 5 or grid.Data[:,:] = numpy.zeros(grid.Shape). Returns and accepts numpy.ndarray, float, and int. Read only.

property DataIsScaled

(bool) If True, the underlying raw data are stored as the UnscaledDataType to save storage space and then transformed by a scaling equation on the fly when they are returned by Data. The raw data can be accessed with UnscaledData. If False, the raw data are returned as is, with no transformation needed, and UnscaledDataType and DataType are the same, and UnscaledData returns the same values as Data. Read only.

property DataType

(str) Numeric data type of the grid, after the scaling function (if any) has been applied to the raw data. numpy.ndarrays returned by Data have this type. Read only. Allowed values꞉ 'int8', 'uint8', 'int16', 'uint16', 'int32', 'uint32', 'float32', 'float64'. Case sensitive.

property Dimensions

(str) Dimensions of this grid. Read only. Allowed values꞉ 'yx', 'zyx', 'tyx', 'tzyx'. Case sensitive.

property DisplayName

(str) Informal name of this object, suitable to be displayed to the user. Read only. Minimum length꞉ 1.

property MaxCoords

(object) Maximum coordinate value for each cell (i.e., the coordinates of the cells’ right edges), indexed using the 1-character dimension of interest and optionally a range to retrieve a numpy.ndarray of coordinates (e.g. MaxCoords['x', 0:4]) or an integer to retrieve a float for a single coordinate (e.g. MaxCoords['x', 10]). Coordinates for the t dimension are returned as datetime instances. Read only.

property MinCoords

(object) Minimum coordinate value for each cell (i.e., the coordinates of the cells’ left edges), indexed using the 1-character dimension of interest and optionally a range to retrieve a numpy.ndarray of coordinates (e.g. MinCoords['x', 0:4]) or an integer to retrieve a float for a single coordinate (e.g. MinCoords['x', 10]). Coordinates for the t dimension are returned as datetime instances. Read only.

property NoDataValue

(object or None) int, float, or single-element numpy array giving the value that indicates that cells of Data should be interpreted as having no data (these are also known as missing, NA, or NULL cells), or None if all cells must have data. Read only.

property ParentCollection

(DatasetCollection or None) Parent DatasetCollection that this object is part of (if any). Read only.

property Shape

(tuple of int) Same length as Dimensions. Length (number of grid cells) of each dimension. Read only.

property TCountPerSemiRegularPeriod

(int or None) Number of time slices per semi-regular period (i.e. per year). None if the grid’s dimensions do not contain a t coordinate or the t coordinate is not semi-regular. Read only.

property TIncrementUnit

(str or None) Unit of the t coordinate. None if the grid’s dimensions do not contain a t coordinate. Read only. Allowed values꞉ 'year', 'month', 'day', 'hour', 'minute', 'second'. Case sensitive.

property TSemiRegularity

(str or None) Type of semi-regularity used for the t coordinate. None if the grid’s dimensions do not contain a t coordinate or the t coordinate is not semi-regular. Read only. Allowed values꞉ 'annual'. Case sensitive.

property UnscaledData

(object) This grid’s data underlying raw data, before it has been transformed by a scaling equation. UnscaledData is indexable using slices (e.g. grid.UnscaledData[:, 5:10, -10:]) or integers (e.g. grid.UnscaledData[0,1,-2]) or both in combination. Strides and negative indexes are supported in the traditional manner. If the grid is writable, UnscaledData can be assigned to write values to the grid, e.g. grid.UnscaledData[0,1] = 5 or grid.UnscaledData[:,:] = numpy.zeros(grid.Shape). Returns and accepts numpy.ndarray, float, and int. Read only.

property UnscaledDataType

(str) Numeric data type of the grid’s raw data, before it has been transformed by a scaling equation. numpy.ndarrays returned by UnscaledData have this type. If no transformation is needed (DataIsScaled is False), then UnscaledDataType and ScaledDataType are the same, and UnscaledData returns the same values as Data. Read only. Allowed values꞉ 'int8', 'uint8', 'int16', 'uint16', 'int32', 'uint32', 'float32', 'float64'. Case sensitive.

property UnscaledNoDataValue

(object or None) int or float value that indicates that cells of UnscaledData should be interpreted as having no data (these are also known as missing, NA, or NULL cells), or None if all cells must have data. Read only.

Methods

Close	Closes any open files or connections associated with this object and releases any other resources allocated to access it.
ConvertSpatialReference	Converts a spatial reference from one format to another, such as an OGC WKT string to a Proj4 string.
DeleteLazyPropertyValue	Deletes the lazy property with the specified name.
GetAllQueryableAttributes	Returns a list of all queryable attributes.
GetIndicesForCoords	Given a tuple or list of coordinates, returns a list of int indices into Data for the cell that contains the coordinates.
GetLazyPropertyValue	Returns the value of the lazy property with the specified name.
GetQueryableAttribute	Returns the queryable attribute with the specified name.
GetQueryableAttributeValue	Returns the value of the queryable attribute with the specified name.
GetQueryableAttributesWithDataType	Returns a list queryable attributes having the specified data type.
GetSpatialReference	Returns the spatial reference of this dataset.
HasLazyPropertyValue	Returns True if the specified lazy property has a value.
SetLazyPropertyValue	Sets the lazy property with the specified name to the specified value.
SetSpatialReference	Sets the spatial reference of this dataset.
TestCapability	Tests whether a capability is supported by this class or an instance of it.
numpy_equal_nan