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- BaseWCSWrapper

# BaseWCSWrapper

class astropy.wcs.wcsapi.BaseWCSWrapper(wcs, *args, **kwargs)

  Bases: `BaseLowLevelWCS`

  A base wrapper class for things that modify Low Level WCSes.

  This wrapper implements a transparent wrapper to many of the properties, with the idea that not all of them would need to be overridden in your wrapper, but some probably will.

  Parameters:
    wcs `astropy.wcs.wcsapi.BaseLowLevelWCS`

      The WCS object to wrap

  Attributes Summary

  `array_shape` | The shape of the data that the WCS applies to as a tuple of length `pixel_n_dim` in `(row, column)` order (the convention for arrays in Python).
  `axis_correlation_matrix` | Returns an (`world_n_dim`, `pixel_n_dim`) matrix that indicates using booleans whether a given world coordinate depends on a given pixel coordinate.
  `pixel_axis_names` | An iterable of strings describing the name for each pixel axis.
  `pixel_bounds` | The bounds (in pixel coordinates) inside which the WCS is defined, as a list with `pixel_n_dim` `(min, max)` tuples.
  `pixel_n_dim` | The number of axes in the pixel coordinate system.
  `pixel_shape` | The shape of the data that the WCS applies to as a tuple of length `pixel_n_dim` in `(x, y)` order (where for an image, `x` is the horizontal coordinate and `y` is the vertical coordinate).
  `serialized_classes` | Indicates whether Python objects are given in serialized form or as actual Python objects.
  `world_axis_names` | An iterable of strings describing the name for each world axis.
  `world_axis_object_classes` | A dictionary giving information on constructing high-level objects for the world coordinates.
  `world_axis_object_components` | A list with `world_n_dim` elements giving information on constructing high-level objects for the world coordinates.
  `world_axis_physical_types` | An iterable of strings describing the physical type for each world axis.
  `world_axis_units` | An iterable of strings given the units of the world coordinates for each axis.
  `world_n_dim` | The number of axes in the world coordinate system.

  Methods Summary

  `array_index_to_world_values`(*index_arrays) | Convert array indices to world coordinates.
  `pixel_to_world_values`(*pixel_arrays) | Convert pixel coordinates to world coordinates.
  `world_to_array_index_values`(*world_arrays) | Convert world coordinates to array indices.
  `world_to_pixel_values`(*world_arrays) | Convert world coordinates to pixel coordinates.

  Attributes Documentation

  array_shape

    The shape of the data that the WCS applies to as a tuple of length `pixel_n_dim` in `(row, column)` order (the convention for arrays in Python).

    If the WCS is valid in the context of a dataset with a particular shape, then this property can be used to store the shape of the data. This can be used for example if implementing slicing of WCS objects. This is an optional property, and it should return `None` if a shape is not known or relevant.

  axis_correlation_matrix
  pixel_axis_names
  pixel_bounds
  pixel_n_dim
  pixel_shape
  serialized_classes
  world_axis_names
  world_axis_object_classes
  world_axis_object_components
  world_axis_physical_types
  world_axis_units
  world_n_dim

  Methods Documentation

  array_index_to_world_values(*index_arrays)

    Convert array indices to world coordinates.

    This is the same as `pixel_to_world_values` except that the indices should be given in `(i, j)` order, where for an image `i` is the row and `j` is the column (i.e. the opposite order to `pixel_to_world_values`).

    If `world_n_dim` is `1`, this method returns a single scalar or array, otherwise a tuple of scalars or arrays is returned.

  abstract pixel_to_world_values(*pixel_arrays)

    Convert pixel coordinates to world coordinates.

    This method takes `pixel_n_dim` scalars or arrays as input, and pixel coordinates should be zero-based. Returns `world_n_dim` scalars or arrays in units given by `world_axis_units`. Note that pixel coordinates are assumed to be 0 at the center of the first pixel in each dimension. If a pixel is in a region where the WCS is not defined, NaN can be returned. The coordinates should be specified in the `(x, y)` order, where for an image, `x` is the horizontal coordinate and `y` is the vertical coordinate.

    If `world_n_dim` is `1`, this method returns a single scalar or array, otherwise a tuple of scalars or arrays is returned.

  world_to_array_index_values(*world_arrays)

    Convert world coordinates to array indices.

    This is the same as `world_to_pixel_values` except that the indices should be returned in `(i, j)` order, where for an image `i` is the row and `j` is the column (i.e. the opposite order to `pixel_to_world_values`). The indices should be returned as rounded integers.

    If `pixel_n_dim` is `1`, this method returns a single scalar or array, otherwise a tuple of scalars or arrays is returned.

  abstract world_to_pixel_values(*world_arrays)

    Convert world coordinates to pixel coordinates.

    This method takes `world_n_dim` scalars or arrays as input in units given by `world_axis_units`. Returns `pixel_n_dim` scalars or arrays. Note that pixel coordinates are assumed to be 0 at the center of the first pixel in each dimension. If a world coordinate does not have a matching pixel coordinate, NaN can be returned. The coordinates should be returned in the `(x, y)` order, where for an image, `x` is the horizontal coordinate and `y` is the vertical coordinate.

    If `pixel_n_dim` is `1`, this method returns a single scalar or array, otherwise a tuple of scalars or arrays is returned.