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from __future__ import annotations |
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from itertools import chain |
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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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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 zip(nan_offsets[:-1], nan_offsets[1:])] |
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