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# SlicedLowLevelWCS

class astropy.wcs.wcsapi.SlicedLowLevelWCS(wcs, slices)

  Bases: `BaseWCSWrapper`

  A Low Level WCS wrapper which applies an array slice to a WCS.

  This class does not modify the underlying WCS object and can therefore drop coupled dimensions as it stores which pixel and world dimensions have been sliced out (or modified) in the underlying WCS and returns the modified results on all the Low Level WCS methods.

  Parameters:
    wcs `BaseLowLevelWCS`

      The WCS to slice.

    slices `slice` or `tuple` or `int`

      A valid array slice to apply to the WCS.

  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.
  `dropped_world_dimensions` | Information describing the dropped world dimensions.
  `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
  axis_correlation_matrix
  dropped_world_dimensions

    Information describing the dropped world dimensions.

  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.

  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 should 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.

  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 should 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.