pyrsgis.raster.shift¶

pyrsgis.raster.shift(ds, x=0, y=0, shift_type='coordinate')[source]¶

Shift the datasource of a raster file

This function can modify the geographic extent in the datasource object of the raster file. When the modified datasource object is used, the exported raster file will be shifted towards a given direction.

Parameters

dsdatasource object: A datasource object of the raster. Ideally, the datasource should be the same as one generated by the pyrsgis.raster.read function.
shift_typestring: Available options are ‘coordinates’ and ‘cell’, which correspond to shifting the datasource either by the projection units of the raster or by number of cells respectively.
xnumber: The amount of shift required in x direction (longitude). Please note that this can not be float value if the shift_type parameter is set to ‘cell’.
ynumber: The amount of shift required in y direction (latitude). Please note that this can not be float value if the shift_type parameter is set to ‘cell’.

Returns

new_dsdatasource object: A new modified datasource object which when used to export a raster will result in a shifted raster file.

Examples

>>> from pyrsgis import raster
>>> infile = r'E:/path_to_your_file/your_file.tif'
>>> ds, data_arr = raster.read(infile)
>>> new_ds = raster.shift(ds, x=10, y=10)
>>> print('Original bounding box:', ds.bbox)
>>> print('Modified bounding box:', new_ds.bbox)
Original geo transform: ([752895.0, 1405185.0], [814215.0, 1466805.0])
Modified geo transform: ([752905.0, 1405195.0], [814225.0, 1466815.0])

Notice that the bounding box values in the ds object have both shifted by 10 units. Negative values can be given to shift the ds onject in the opposite direction.

The ds object can also be shifted by number of cells by switching the shift_type parameter.

>>> new_ds = raster.shift(ds, x=10, y=10, shift_type='cell')
>>> print('Modified bounding box:', new_ds.GeoTransform)
Modified geo transform: ([753195.0, 1405485.0], [814515.0, 1467105.0])

Notice that the modified ds object is now shifted by 10*cell size (30 - a Landsat data used for demonstration).

The modified ds object can be used to export raste file.

>>> raster.export(data_arr, new_ds, r'E:/path_to_your_file/shifted_file.tif')