def random_grid(self, width, height, count, units='native'):
"""Create a dataframe that defines a random set of samples.
The width and height are given in pixels and multiplied by the
pixel size of the raster to create samples at the native
resolution of the raster.
Note: width and height unrelated to the DL model inputs.
Args:
width (int): sample size in pixels
height (int): sample size in pixels
units (str): units applied to sample sizes ('native' or 'pixels')
count (int): number of samples
Returns:
(GeoDataframe)
"""
if not self.src:
raise RuntimeError('source not set or failed to open')
if units == 'pixels':
dims = width * self.src.res[0], height * self.src.res[1]
elif units == 'native':
dims = width, height
else:
raise ValueError('units must be "native" or "pixels"')
gdf = grid.random_grid(*self.src.bounds, *dims, count)
gdf.crs = self.src.crs
return gdf
def random_grid(self, width, height, count, units='native'):
"""Create a dataframe that defines a random set of samples.
When units='native', width and height are given in projection
units (i.e. meters, feet, etc). The number of pixels within this
area would depend on the pixel size. If units='pixel', width
and height are multiplied by the pixel size to compute the
sample boundaries.
Note: width and height are unrelated to the DL model inputs.
Args:
width (int): sample size in pixels
height (int): sample size in pixels
units (str): units applied to sample sizes ('native' or 'pixels')
count (int): number of samples
Returns:
(GeoDataframe)
"""
if not self.src:
raise RuntimeError('source not set or failed to open')
if units == 'pixels':
dims = width * self.src.res[0], height * self.src.res[1]
elif units == 'native':
dims = width, height
else:
raise ValueError('units must be "native" or "pixels"')
gdf = grid.random_grid(*self.src.bounds, *dims, count)
gdf.crs = self.src.crs
return gdf
def random_grid(self, count, width=0, height=0):
"""Create a dataframe that defines a random set of samples.
The width and height are given in pixels and multiplied by the
pixel size of the raster to create samples at the native
resolution of the raster.
Args:
width (int): sample size in pixels
height (int): sample size in pixels
count (int): number of samples
Returns:
(GeoDataframe)
"""
width = width if width else self.width
height = height if height else self.height
if width < 1 or height < 1:
raise ValueError('width and height must be specified')
if not self.src:
raise RuntimeError('source not set or failed to open')
dims = width * self.src.res[0], height * self.src.res[1]
gdf = grid.random_grid(*self.src.bounds, *dims, count)
gdf.crs = self.src.crs
return gdf
def test_random_grid():
bounds, _, _ = grid.raster_meta('data/small.tif')
size = (bounds[2]-bounds[0], bounds[3]-bounds[1])
size = [i/10 for i in size]
df = grid.random_grid(*bounds, *size, count=100)
assert len(df) == 100
assert df.total_bounds[0] >= bounds[0]
assert df.total_bounds[1] >= bounds[1]
assert df.total_bounds[2] <= bounds[2]
assert df.total_bounds[3] <= bounds[3]