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1""" 

2Module of functions that are like ufuncs in acting on arrays and optionally 

3storing results in an output array. 

4 

5""" 

6__all__ = ['fix', 'isneginf', 'isposinf'] 

7 

8import numpy.core.numeric as nx 

9from numpy.core.overrides import ( 

10 array_function_dispatch, ARRAY_FUNCTION_ENABLED, 

11) 

12import warnings 

13import functools 

14 

15 

16def _deprecate_out_named_y(f): 

17 """ 

18 Allow the out argument to be passed as the name `y` (deprecated) 

19 

20 In future, this decorator should be removed. 

21 """ 

22 @functools.wraps(f) 

23 def func(x, out=None, **kwargs): 

24 if 'y' in kwargs: 

25 if 'out' in kwargs: 

26 raise TypeError( 

27 "{} got multiple values for argument 'out'/'y'" 

28 .format(f.__name__) 

29 ) 

30 out = kwargs.pop('y') 

31 # NumPy 1.13.0, 2017-04-26 

32 warnings.warn( 

33 "The name of the out argument to {} has changed from `y` to " 

34 "`out`, to match other ufuncs.".format(f.__name__), 

35 DeprecationWarning, stacklevel=3) 

36 return f(x, out=out, **kwargs) 

37 

38 return func 

39 

40 

41def _fix_out_named_y(f): 

42 """ 

43 Allow the out argument to be passed as the name `y` (deprecated) 

44 

45 This decorator should only be used if _deprecate_out_named_y is used on 

46 a corresponding dispatcher function. 

47 """ 

48 @functools.wraps(f) 

49 def func(x, out=None, **kwargs): 

50 if 'y' in kwargs: 

51 # we already did error checking in _deprecate_out_named_y 

52 out = kwargs.pop('y') 

53 return f(x, out=out, **kwargs) 

54 

55 return func 

56 

57 

58def _fix_and_maybe_deprecate_out_named_y(f): 

59 """ 

60 Use the appropriate decorator, depending upon if dispatching is being used. 

61 """ 

62 if ARRAY_FUNCTION_ENABLED: 

63 return _fix_out_named_y(f) 

64 else: 

65 return _deprecate_out_named_y(f) 

66 

67 

68@_deprecate_out_named_y 

69def _dispatcher(x, out=None): 

70 return (x, out) 

71 

72 

73@array_function_dispatch(_dispatcher, verify=False, module='numpy') 

74@_fix_and_maybe_deprecate_out_named_y 

75def fix(x, out=None): 

76 """ 

77 Round to nearest integer towards zero. 

78 

79 Round an array of floats element-wise to nearest integer towards zero. 

80 The rounded values are returned as floats. 

81 

82 Parameters 

83 ---------- 

84 x : array_like 

85 An array of floats to be rounded 

86 out : ndarray, optional 

87 A location into which the result is stored. If provided, it must have 

88 a shape that the input broadcasts to. If not provided or None, a 

89 freshly-allocated array is returned. 

90 

91 Returns 

92 ------- 

93 out : ndarray of floats 

94 A float array with the same dimensions as the input. 

95 If second argument is not supplied then a float array is returned 

96 with the rounded values. 

97 

98 If a second argument is supplied the result is stored there. 

99 The return value `out` is then a reference to that array. 

100 

101 See Also 

102 -------- 

103 trunc, floor, ceil 

104 around : Round to given number of decimals 

105 

106 Examples 

107 -------- 

108 >>> np.fix(3.14) 

109 3.0 

110 >>> np.fix(3) 

111 3.0 

112 >>> np.fix([2.1, 2.9, -2.1, -2.9]) 

113 array([ 2., 2., -2., -2.]) 

114 

115 """ 

116 # promote back to an array if flattened 

117 res = nx.asanyarray(nx.ceil(x, out=out)) 

118 res = nx.floor(x, out=res, where=nx.greater_equal(x, 0)) 

119 

120 # when no out argument is passed and no subclasses are involved, flatten 

121 # scalars 

122 if out is None and type(res) is nx.ndarray: 

123 res = res[()] 

124 return res 

125 

126 

127@array_function_dispatch(_dispatcher, verify=False, module='numpy') 

128@_fix_and_maybe_deprecate_out_named_y 

129def isposinf(x, out=None): 

130 """ 

131 Test element-wise for positive infinity, return result as bool array. 

132 

133 Parameters 

134 ---------- 

135 x : array_like 

136 The input array. 

137 out : array_like, optional 

138 A location into which the result is stored. If provided, it must have a 

139 shape that the input broadcasts to. If not provided or None, a 

140 freshly-allocated boolean array is returned. 

141 

142 Returns 

143 ------- 

144 out : ndarray 

145 A boolean array with the same dimensions as the input. 

146 If second argument is not supplied then a boolean array is returned 

147 with values True where the corresponding element of the input is 

148 positive infinity and values False where the element of the input is 

149 not positive infinity. 

150 

151 If a second argument is supplied the result is stored there. If the 

152 type of that array is a numeric type the result is represented as zeros 

153 and ones, if the type is boolean then as False and True. 

154 The return value `out` is then a reference to that array. 

155 

156 See Also 

157 -------- 

158 isinf, isneginf, isfinite, isnan 

159 

160 Notes 

161 ----- 

162 NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic 

163 (IEEE 754). 

164 

165 Errors result if the second argument is also supplied when x is a scalar 

166 input, if first and second arguments have different shapes, or if the 

167 first argument has complex values 

168 

169 Examples 

170 -------- 

171 >>> np.isposinf(np.PINF) 

172 True 

173 >>> np.isposinf(np.inf) 

174 True 

175 >>> np.isposinf(np.NINF) 

176 False 

177 >>> np.isposinf([-np.inf, 0., np.inf]) 

178 array([False, False, True]) 

179 

180 >>> x = np.array([-np.inf, 0., np.inf]) 

181 >>> y = np.array([2, 2, 2]) 

182 >>> np.isposinf(x, y) 

183 array([0, 0, 1]) 

184 >>> y 

185 array([0, 0, 1]) 

186 

187 """ 

188 is_inf = nx.isinf(x) 

189 try: 

190 signbit = ~nx.signbit(x) 

191 except TypeError as e: 

192 raise TypeError('This operation is not supported for complex values ' 

193 'because it would be ambiguous.') from e 

194 else: 

195 return nx.logical_and(is_inf, signbit, out) 

196 

197 

198@array_function_dispatch(_dispatcher, verify=False, module='numpy') 

199@_fix_and_maybe_deprecate_out_named_y 

200def isneginf(x, out=None): 

201 """ 

202 Test element-wise for negative infinity, return result as bool array. 

203 

204 Parameters 

205 ---------- 

206 x : array_like 

207 The input array. 

208 out : array_like, optional 

209 A location into which the result is stored. If provided, it must have a 

210 shape that the input broadcasts to. If not provided or None, a 

211 freshly-allocated boolean array is returned. 

212 

213 Returns 

214 ------- 

215 out : ndarray 

216 A boolean array with the same dimensions as the input. 

217 If second argument is not supplied then a numpy boolean array is 

218 returned with values True where the corresponding element of the 

219 input is negative infinity and values False where the element of 

220 the input is not negative infinity. 

221 

222 If a second argument is supplied the result is stored there. If the 

223 type of that array is a numeric type the result is represented as 

224 zeros and ones, if the type is boolean then as False and True. The 

225 return value `out` is then a reference to that array. 

226 

227 See Also 

228 -------- 

229 isinf, isposinf, isnan, isfinite 

230 

231 Notes 

232 ----- 

233 NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic 

234 (IEEE 754). 

235 

236 Errors result if the second argument is also supplied when x is a scalar 

237 input, if first and second arguments have different shapes, or if the 

238 first argument has complex values. 

239 

240 Examples 

241 -------- 

242 >>> np.isneginf(np.NINF) 

243 True 

244 >>> np.isneginf(np.inf) 

245 False 

246 >>> np.isneginf(np.PINF) 

247 False 

248 >>> np.isneginf([-np.inf, 0., np.inf]) 

249 array([ True, False, False]) 

250 

251 >>> x = np.array([-np.inf, 0., np.inf]) 

252 >>> y = np.array([2, 2, 2]) 

253 >>> np.isneginf(x, y) 

254 array([1, 0, 0]) 

255 >>> y 

256 array([1, 0, 0]) 

257 

258 """ 

259 is_inf = nx.isinf(x) 

260 try: 

261 signbit = nx.signbit(x) 

262 except TypeError as e: 

263 raise TypeError('This operation is not supported for complex values ' 

264 'because it would be ambiguous.') from e 

265 else: 

266 return nx.logical_and(is_inf, signbit, out)