262 lines
8.8 KiB
Python
262 lines
8.8 KiB
Python
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from __future__ import annotations
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from itertools import chain, pairwise
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from typing import TYPE_CHECKING
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import numpy as np
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from contourpy.typecheck import check_code_array, check_offset_array, check_point_array
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from contourpy.types import CLOSEPOLY, LINETO, MOVETO, code_dtype, offset_dtype, point_dtype
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if TYPE_CHECKING:
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import contourpy._contourpy as cpy
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def codes_from_offsets(offsets: cpy.OffsetArray) -> cpy.CodeArray:
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"""Determine codes from offsets, assuming they all correspond to closed polygons.
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"""
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check_offset_array(offsets)
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n = offsets[-1]
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codes = np.full(n, LINETO, dtype=code_dtype)
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codes[offsets[:-1]] = MOVETO
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codes[offsets[1:] - 1] = CLOSEPOLY
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return codes
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def codes_from_offsets_and_points(
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offsets: cpy.OffsetArray,
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points: cpy.PointArray,
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) -> cpy.CodeArray:
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"""Determine codes from offsets and points, using the equality of the start and end points of
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each line to determine if lines are closed or not.
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"""
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check_offset_array(offsets)
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check_point_array(points)
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codes = np.full(len(points), LINETO, dtype=code_dtype)
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codes[offsets[:-1]] = MOVETO
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end_offsets = offsets[1:] - 1
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closed = np.all(points[offsets[:-1]] == points[end_offsets], axis=1)
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codes[end_offsets[closed]] = CLOSEPOLY
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return codes
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def codes_from_points(points: cpy.PointArray) -> cpy.CodeArray:
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"""Determine codes for a single line, using the equality of the start and end points to
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determine if the line is closed or not.
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"""
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check_point_array(points)
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n = len(points)
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codes = np.full(n, LINETO, dtype=code_dtype)
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codes[0] = MOVETO
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if np.all(points[0] == points[-1]):
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codes[-1] = CLOSEPOLY
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return codes
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def concat_codes(list_of_codes: list[cpy.CodeArray]) -> cpy.CodeArray:
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"""Concatenate a list of codes arrays into a single code array.
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"""
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if not list_of_codes:
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raise ValueError("Empty list passed to concat_codes")
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return np.concatenate(list_of_codes, dtype=code_dtype)
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def concat_codes_or_none(list_of_codes_or_none: list[cpy.CodeArray | None]) -> cpy.CodeArray | None:
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"""Concatenate a list of codes arrays or None into a single code array or None.
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"""
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list_of_codes = [codes for codes in list_of_codes_or_none if codes is not None]
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if list_of_codes:
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return concat_codes(list_of_codes)
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else:
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return None
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def concat_offsets(list_of_offsets: list[cpy.OffsetArray]) -> cpy.OffsetArray:
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"""Concatenate a list of offsets arrays into a single offset array.
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"""
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if not list_of_offsets:
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raise ValueError("Empty list passed to concat_offsets")
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n = len(list_of_offsets)
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cumulative = np.cumsum([offsets[-1] for offsets in list_of_offsets], dtype=offset_dtype)
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ret: cpy.OffsetArray = np.concatenate(
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(list_of_offsets[0], *(list_of_offsets[i+1][1:] + cumulative[i] for i in range(n-1))),
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dtype=offset_dtype,
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)
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return ret
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def concat_offsets_or_none(
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list_of_offsets_or_none: list[cpy.OffsetArray | None],
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) -> cpy.OffsetArray | None:
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"""Concatenate a list of offsets arrays or None into a single offset array or None.
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"""
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list_of_offsets = [offsets for offsets in list_of_offsets_or_none if offsets is not None]
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if list_of_offsets:
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return concat_offsets(list_of_offsets)
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else:
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return None
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def concat_points(list_of_points: list[cpy.PointArray]) -> cpy.PointArray:
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"""Concatenate a list of point arrays into a single point array.
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"""
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if not list_of_points:
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raise ValueError("Empty list passed to concat_points")
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return np.concatenate(list_of_points, dtype=point_dtype)
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def concat_points_or_none(
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list_of_points_or_none: list[cpy.PointArray | None],
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) -> cpy.PointArray | None:
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"""Concatenate a list of point arrays or None into a single point array or None.
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"""
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list_of_points = [points for points in list_of_points_or_none if points is not None]
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if list_of_points:
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return concat_points(list_of_points)
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else:
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return None
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def concat_points_or_none_with_nan(
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list_of_points_or_none: list[cpy.PointArray | None],
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) -> cpy.PointArray | None:
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"""Concatenate a list of points or None into a single point array or None, with NaNs used to
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separate each line.
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"""
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list_of_points = [points for points in list_of_points_or_none if points is not None]
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if list_of_points:
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return concat_points_with_nan(list_of_points)
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else:
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return None
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def concat_points_with_nan(list_of_points: list[cpy.PointArray]) -> cpy.PointArray:
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"""Concatenate a list of points into a single point array with NaNs used to separate each line.
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"""
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if not list_of_points:
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raise ValueError("Empty list passed to concat_points_with_nan")
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if len(list_of_points) == 1:
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return list_of_points[0]
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else:
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nan_spacer = np.full((1, 2), np.nan, dtype=point_dtype)
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list_of_points = [list_of_points[0],
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*list(chain(*((nan_spacer, x) for x in list_of_points[1:])))]
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return concat_points(list_of_points)
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def insert_nan_at_offsets(points: cpy.PointArray, offsets: cpy.OffsetArray) -> cpy.PointArray:
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"""Insert NaNs into a point array at locations specified by an offset array.
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"""
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check_point_array(points)
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check_offset_array(offsets)
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if len(offsets) <= 2:
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return points
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else:
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nan_spacer = np.array([np.nan, np.nan], dtype=point_dtype)
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# Convert offsets to int64 to avoid numpy error when mixing signed and unsigned ints.
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return np.insert(points, offsets[1:-1].astype(np.int64), nan_spacer, axis=0)
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def offsets_from_codes(codes: cpy.CodeArray) -> cpy.OffsetArray:
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"""Determine offsets from codes using locations of MOVETO codes.
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"""
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check_code_array(codes)
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return np.append(np.nonzero(codes == MOVETO)[0], len(codes)).astype(offset_dtype)
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def offsets_from_lengths(list_of_points: list[cpy.PointArray]) -> cpy.OffsetArray:
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"""Determine offsets from lengths of point arrays.
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"""
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if not list_of_points:
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raise ValueError("Empty list passed to offsets_from_lengths")
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return np.cumsum([0] + [len(line) for line in list_of_points], dtype=offset_dtype)
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def outer_offsets_from_list_of_codes(list_of_codes: list[cpy.CodeArray]) -> cpy.OffsetArray:
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"""Determine outer offsets from codes using locations of MOVETO codes.
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"""
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if not list_of_codes:
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raise ValueError("Empty list passed to outer_offsets_from_list_of_codes")
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return np.cumsum([0] + [np.count_nonzero(codes == MOVETO) for codes in list_of_codes],
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dtype=offset_dtype)
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def outer_offsets_from_list_of_offsets(list_of_offsets: list[cpy.OffsetArray]) -> cpy.OffsetArray:
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"""Determine outer offsets from a list of offsets.
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"""
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if not list_of_offsets:
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raise ValueError("Empty list passed to outer_offsets_from_list_of_offsets")
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return np.cumsum([0] + [len(offsets)-1 for offsets in list_of_offsets], dtype=offset_dtype)
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def remove_nan(points: cpy.PointArray) -> tuple[cpy.PointArray, cpy.OffsetArray]:
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"""Remove NaN from a points array, also return the offsets corresponding to the NaN removed.
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"""
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check_point_array(points)
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nan_offsets = np.nonzero(np.isnan(points[:, 0]))[0]
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if len(nan_offsets) == 0:
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return points, np.array([0, len(points)], dtype=offset_dtype)
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else:
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points = np.delete(points, nan_offsets, axis=0)
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nan_offsets -= np.arange(len(nan_offsets))
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offsets: cpy.OffsetArray = np.empty(len(nan_offsets)+2, dtype=offset_dtype)
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offsets[0] = 0
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offsets[1:-1] = nan_offsets
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offsets[-1] = len(points)
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return points, offsets
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def split_codes_by_offsets(codes: cpy.CodeArray, offsets: cpy.OffsetArray) -> list[cpy.CodeArray]:
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"""Split a code array at locations specified by an offset array into a list of code arrays.
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"""
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check_code_array(codes)
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check_offset_array(offsets)
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if len(offsets) > 2:
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return np.split(codes, offsets[1:-1])
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else:
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return [codes]
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def split_points_by_offsets(
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points: cpy.PointArray,
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offsets: cpy.OffsetArray,
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) -> list[cpy.PointArray]:
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"""Split a point array at locations specified by an offset array into a list of point arrays.
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"""
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check_point_array(points)
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check_offset_array(offsets)
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if len(offsets) > 2:
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return np.split(points, offsets[1:-1])
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else:
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return [points]
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def split_points_at_nan(points: cpy.PointArray) -> list[cpy.PointArray]:
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"""Split a points array at NaNs into a list of point arrays.
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"""
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check_point_array(points)
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nan_offsets = np.nonzero(np.isnan(points[:, 0]))[0]
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if len(nan_offsets) == 0:
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return [points]
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else:
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nan_offsets = np.concatenate(([-1], nan_offsets, [len(points)]))
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return [points[s+1:e] for s, e in pairwise(nan_offsets)]
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