drop_axis

pyhelpers.geom.drop_axis(geom, axis='z', as_array=False)

Drop an axis from a given 3D geometry object.

Parameters

• geom (shapely.geometry object) – geometry object that has x, y and z coordinates

• axis (str) – options include ‘x’, ‘y’ and ‘z’, defaults to 'z'

• as_array (bool) – whether to return an array, defaults to False

Returns

geometry object (or an array) without the specified axis

Return type

shapely.geometry object or numpy.ndarray

Examples:

>>> from pyhelpers.geom import drop_axis
>>> from shapely.geometry import Point, LineString, Polygon, MultiLineString

>>> geom_1 = Point([1, 2, 3])
>>> geom_1.wkt
'POINT Z (1 2 3)'
>>> geom_1_ = drop_axis(geom_1, 'x')
>>> geom_1_.wkt
'POINT (2 3)'
>>> geom_1_ = drop_axis(geom_1, 'x', as_array=True)
>>> geom_1_
array([2., 3.])

>>> geom_2 = LineString([[1, 2, 3], [2, 3, 4], [3, 4, 5]])
>>> geom_2.wkt
'LINESTRING Z (1 2 3, 2 3 4, 3 4 5)'
>>> geom_2_ = drop_axis(geom_2, 'y')
>>> geom_2_.wkt
'LINESTRING (1 3, 2 4, 3 5)'
>>> geom_2_ = drop_axis(geom_2, 'y', as_array=True)
>>> geom_2_
array([[1., 3.],
       [2., 4.],
       [3., 5.]])

>>> geom_3 = Polygon([[6, 3, 5], [6, 3, 0], [6, 1, 0], [6, 1, 5], [6, 3, 5]])
>>> geom_3.wkt
'POLYGON Z ((6 3 5, 6 3 0, 6 1 0, 6 1 5, 6 3 5))'
>>> geom_3_ = drop_axis(geom_3, 'z')
>>> geom_3_.wkt
'POLYGON ((6 3, 6 3, 6 1, 6 1, 6 3))'
>>> geom_3_ = drop_axis(geom_3, 'z', as_array=True)
>>> geom_3_
array([[6., 3.],
       [6., 3.],
       [6., 1.],
       [6., 1.],
       [6., 3.]])

>>> ls1 = LineString([[1, 2, 3], [2, 3, 4], [3, 4, 5]])
>>> ls2 = LineString([[2, 3, 4], [1, 2, 3], [3, 4, 5]])
>>> geom_4 = MultiLineString([ls1, ls2])
>>> geom_4.wkt
'MULTILINESTRING Z ((1 2 3, 2 3 4, 3 4 5), (2 3 4, 1 2 3, 3 4 5))'
>>> geom_4_ = drop_axis(geom_4, 'z')
>>> geom_4_.wkt
'MULTILINESTRING ((1 2, 2 3, 3 4), (2 3, 1 2, 3 4))'
>>> geom_4_ = drop_axis(geom_4, 'z', as_array=True)
>>> geom_4_
array([[[1., 2.],
        [2., 3.],
        [3., 4.]],

       [[2., 3.],
        [1., 2.],
        [3., 4.]]])