90 lines
3.0 KiB
Python
90 lines
3.0 KiB
Python
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"""
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Utility functions used within pyproj
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"""
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from array import array
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from typing import Any, Tuple
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def _copytobuffer_return_scalar(xx: Any) -> Tuple[array, bool, bool, bool]:
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"""
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Parameters
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-----------
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xx: float or 0-d numpy array
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"""
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try:
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# inx,isfloat,islist,istuple
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return array("d", (float(xx),)), True, False, False
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except Exception:
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raise TypeError("input must be a scalar")
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def _copytobuffer(xx: Any) -> Tuple[Any, bool, bool, bool]:
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"""
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return a copy of xx as an object that supports the python Buffer
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API (python array if input is float, list or tuple, numpy array
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if input is a numpy array). returns copyofx, isfloat, islist,
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istuple (islist is True if input is a list, istuple is true if
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input is a tuple, isfloat is true if input is a float).
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"""
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# make sure x supports Buffer API and contains doubles.
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isfloat = False
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islist = False
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istuple = False
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# first, if it's a numpy array scalar convert to float
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# (array scalars don't support buffer API)
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if hasattr(xx, "shape"):
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if xx.shape == ():
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return _copytobuffer_return_scalar(xx)
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else:
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try:
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# typecast numpy arrays to double.
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# (this makes a copy - which is crucial
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# since buffer is modified in place)
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xx.dtype.char
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# Basemap issue
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# https://github.com/matplotlib/basemap/pull/223/files
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# (deal with input array in fortran order)
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inx = xx.copy(order="C").astype("d")
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# inx,isfloat,islist,istuple
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return inx, False, False, False
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except Exception:
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try: # perhaps they are Numeric/numarrays?
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# sorry, not tested yet.
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# i don't know Numeric/numarrays has `shape'.
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xx.typecode()
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inx = xx.astype("d")
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# inx,isfloat,islist,istuple
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return inx, False, False, False
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except Exception:
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raise TypeError("input must be an array, list, tuple or scalar")
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else:
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# perhaps they are regular python arrays?
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if hasattr(xx, "typecode"):
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# xx.typecode
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inx = array("d", xx)
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# try to convert to python array
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# a list.
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elif type(xx) == list:
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inx = array("d", xx)
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islist = True
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# a tuple.
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elif type(xx) == tuple:
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inx = array("d", xx)
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istuple = True
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# a scalar?
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else:
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return _copytobuffer_return_scalar(xx)
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return inx, isfloat, islist, istuple
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def _convertback(isfloat: bool, islist: bool, istuple: bool, inx: Any) -> Any:
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# if inputs were lists, tuples or floats, convert back to original type.
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if isfloat:
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return inx[0]
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elif islist:
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return inx.tolist()
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elif istuple:
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return tuple(inx)
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else:
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return inx
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