Coverage for install/scipp/core/dimensions.py: 69%

1# SPDX-License-Identifier: BSD-3-Clause 

2# Copyright (c) 2023 Scipp contributors (https://github.com/scipp) 

3# @author Simon Heybrock 

4from typing import Optional 

5 

6from .._scipp.core import CoordError, DataArray, Dataset, Variable 

7from ..typing import VariableLikeType 

8from .argument_handlers import combine_dict_args 

9from .bins import bins 

10from .variable import scalar 

11 

12 

13def _rename_dims( 

14 self: VariableLikeType, dims_dict: Optional[dict[str, str]] = None, /, **names: str 

15) -> VariableLikeType: 

16 """Rename dimensions. 

17 

18 The renaming can be defined: 

19 

20 - using a dict mapping the old to new names, e.g. 

21 ``rename_dims({'x': 'a', 'y': 'b'})`` 

22 - using keyword arguments, e.g. ``rename_dims(x='a', y='b')`` 

23 

24 In both cases, x is renamed to a and y to b. 

25 

26 Dimensions not specified in either input are unchanged. 

27 

28 This function only renames dimensions. 

29 See the ``rename`` method to also rename coordinates and attributes. 

30 

31 Parameters 

32 ---------- 

33 dims_dict: 

34 Dictionary mapping old to new names. 

35 names: 

36 Mapping of old to new names as keyword arguments. 

37 

38 Returns 

39 ------- 

40 : 

41 A new object with renamed dimensions. 

42 """ 

43 return self._rename_dims(combine_dict_args(dims_dict, names)) 

44 

45 

46def _rename_variable( 

47 var: Variable, dims_dict: Optional[dict[str, str]] = None, /, **names: str 

48) -> Variable: 

49 """Rename dimension labels. 

50 

51 The renaming can be defined: 

52 

53 - using a dict mapping the old to new names, e.g. ``rename({'x': 'a', 'y': 'b'})`` 

54 - using keyword arguments, e.g. ``rename(x='a', y='b')`` 

55 

56 In both cases, x is renamed to a and y to b. 

57 

58 Dimensions not specified in either input are unchanged. 

59 

60 Parameters 

61 ---------- 

62 dims_dict: 

63 Dictionary mapping old to new names. 

64 names: 

65 Mapping of old to new names as keyword arguments. 

66 

67 Returns 

68 ------- 

69 : 

70 A new variable with renamed dimensions which shares a buffer with the input. 

71 

72 See Also 

73 -------- 

74 scipp.Variable.rename_dims: 

75 Equivalent for ``Variable`` but differs for ``DataArray`` and ``Dataset``. 

76 """ 

77 return var.rename_dims(combine_dict_args(dims_dict, names)) 

78 

79 

80def _rename_data_array( 

81 da: DataArray, dims_dict: Optional[dict[str, str]] = None, /, **names: str 

82) -> DataArray: 

83 """Rename the dimensions, coordinates, and attributes. 

84 

85 The renaming can be defined: 

86 

87 - using a dict mapping the old to new names, e.g. ``rename({'x': 'a', 'y': 'b'})`` 

88 - using keyword arguments, e.g. ``rename(x='a', y='b')`` 

89 

90 In both cases, x is renamed to a and y to b. 

91 

92 Names not specified in either input are unchanged. 

93 

94 Parameters 

95 ---------- 

96 dims_dict: 

97 Dictionary mapping old to new names. 

98 names: 

99 Mapping of old to new names as keyword arguments. 

100 

101 Returns 

102 ------- 

103 : 

104 A new data array with renamed dimensions, coordinates, and attributes. 

105 Buffers are shared with the input. 

106 

107 See Also 

108 -------- 

109 scipp.DataArray.rename_dims: 

110 Only rename dimensions, not coordinates and attributes. 

111 """ 

112 renaming_dict = combine_dict_args(dims_dict, names) 

113 out = da.rename_dims(renaming_dict) 

114 if out.bins is not None: 

115 out.data = bins(**out.bins.constituents) 

116 for old, new in renaming_dict.items(): 

117 if new in out.deprecated_meta: 

118 raise CoordError( 

119 f"Cannot rename '{old}' to '{new}', since a coord or attr named {new} " 

120 "already exists." 

121 ) 

122 for meta in (out.coords, out.deprecated_attrs): 

123 if old in meta: 

124 meta[new] = meta.pop(old) 

125 if out.bins is not None: 

126 for meta in (out.bins.coords, out.bins.deprecated_attrs): 

127 if old in meta: 

128 meta[new] = meta.pop(old) 

129 return out 

130 

131 

132def _rename_dataset( 

133 ds: Dataset, dims_dict: Optional[dict[str, str]] = None, /, **names: str 

134) -> Dataset: 

135 """Rename the dimensions, coordinates and attributes of all the items. 

136 

137 The renaming can be defined: 

138 

139 - using a dict mapping the old to new names, e.g. ``rename({'x': 'a', 'y': 'b'})`` 

140 - using keyword arguments, e.g. ``rename(x='a', y='b')`` 

141 

142 In both cases, x is renamed to a and y to b. 

143 

144 Names not specified in either input are unchanged. 

145 

146 Parameters 

147 ---------- 

148 dims_dict: 

149 Dictionary mapping old to new names. 

150 names: 

151 Mapping of old to new names as keyword arguments. 

152 

153 Returns 

154 ------- 

155 : 

156 A new dataset with renamed dimensions, coordinates, and attributes. 

157 Buffers are shared with the input. 

158 

159 See Also 

160 -------- 

161 scipp.Dataset.rename_dims: 

162 Only rename dimensions, not coordinates and attributes. 

163 """ 

164 dims_dict = combine_dict_args(dims_dict, names) 

165 if len(ds) != 0: 

166 return Dataset( 

167 {key: _rename_data_array(value, dims_dict) for key, value in ds.items()} 

168 ) 

169 # This relies on broadcast and DataArray.__init__ not making copies 

170 # to avoid allocating too much extra memory. 

171 dummy = DataArray( 

172 scalar(0).broadcast(dims=ds.dims, shape=ds.shape), coords=ds.coords 

173 ) 

174 return Dataset(coords=_rename_data_array(dummy, dims_dict).coords)