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1""" 

2A sub-package for efficiently dealing with polynomials. 

3 

4Within the documentation for this sub-package, a "finite power series," 

5i.e., a polynomial (also referred to simply as a "series") is represented 

6by a 1-D numpy array of the polynomial's coefficients, ordered from lowest 

7order term to highest. For example, array([1,2,3]) represents 

8``P_0 + 2*P_1 + 3*P_2``, where P_n is the n-th order basis polynomial 

9applicable to the specific module in question, e.g., `polynomial` (which 

10"wraps" the "standard" basis) or `chebyshev`. For optimal performance, 

11all operations on polynomials, including evaluation at an argument, are 

12implemented as operations on the coefficients. Additional (module-specific) 

13information can be found in the docstring for the module of interest. 

14 

15This package provides *convenience classes* for each of six different kinds 

16of polynomials: 

17 

18 ======================== ================ 

19 **Name** **Provides** 

20 ======================== ================ 

21 `~polynomial.Polynomial` Power series 

22 `~chebyshev.Chebyshev` Chebyshev series 

23 `~legendre.Legendre` Legendre series 

24 `~laguerre.Laguerre` Laguerre series 

25 `~hermite.Hermite` Hermite series 

26 `~hermite_e.HermiteE` HermiteE series 

27 ======================== ================ 

28 

29These *convenience classes* provide a consistent interface for creating, 

30manipulating, and fitting data with polynomials of different bases. 

31The convenience classes are the preferred interface for the `~numpy.polynomial` 

32package, and are available from the ``numpy.polynomial`` namespace. 

33This eliminates the need to navigate to the corresponding submodules, e.g. 

34``np.polynomial.Polynomial`` or ``np.polynomial.Chebyshev`` instead of 

35``np.polynomial.polynomial.Polynomial`` or 

36``np.polynomial.chebyshev.Chebyshev``, respectively. 

37The classes provide a more consistent and concise interface than the 

38type-specific functions defined in the submodules for each type of polynomial. 

39For example, to fit a Chebyshev polynomial with degree ``1`` to data given 

40by arrays ``xdata`` and ``ydata``, the 

41`~chebyshev.Chebyshev.fit` class method:: 

42 

43 >>> from numpy.polynomial import Chebyshev 

44 >>> c = Chebyshev.fit(xdata, ydata, deg=1) 

45 

46is preferred over the `chebyshev.chebfit` function from the 

47``np.polynomial.chebyshev`` module:: 

48 

49 >>> from numpy.polynomial.chebyshev import chebfit 

50 >>> c = chebfit(xdata, ydata, deg=1) 

51 

52See :doc:`routines.polynomials.classes` for more details. 

53 

54Convenience Classes 

55=================== 

56 

57The following lists the various constants and methods common to all of 

58the classes representing the various kinds of polynomials. In the following, 

59the term ``Poly`` represents any one of the convenience classes (e.g. 

60`~polynomial.Polynomial`, `~chebyshev.Chebyshev`, `~hermite.Hermite`, etc.) 

61while the lowercase ``p`` represents an **instance** of a polynomial class. 

62 

63Constants 

64--------- 

65 

66- ``Poly.domain`` -- Default domain 

67- ``Poly.window`` -- Default window 

68- ``Poly.basis_name`` -- String used to represent the basis 

69- ``Poly.maxpower`` -- Maximum value ``n`` such that ``p**n`` is allowed 

70- ``Poly.nickname`` -- String used in printing 

71 

72Creation 

73-------- 

74 

75Methods for creating polynomial instances. 

76 

77- ``Poly.basis(degree)`` -- Basis polynomial of given degree 

78- ``Poly.identity()`` -- ``p`` where ``p(x) = x`` for all ``x`` 

79- ``Poly.fit(x, y, deg)`` -- ``p`` of degree ``deg`` with coefficients 

80 determined by the least-squares fit to the data ``x``, ``y`` 

81- ``Poly.fromroots(roots)`` -- ``p`` with specified roots 

82- ``p.copy()`` -- Create a copy of ``p`` 

83 

84Conversion 

85---------- 

86 

87Methods for converting a polynomial instance of one kind to another. 

88 

89- ``p.cast(Poly)`` -- Convert ``p`` to instance of kind ``Poly`` 

90- ``p.convert(Poly)`` -- Convert ``p`` to instance of kind ``Poly`` or map 

91 between ``domain`` and ``window`` 

92 

93Calculus 

94-------- 

95- ``p.deriv()`` -- Take the derivative of ``p`` 

96- ``p.integ()`` -- Integrate ``p`` 

97 

98Validation 

99---------- 

100- ``Poly.has_samecoef(p1, p2)`` -- Check if coefficients match 

101- ``Poly.has_samedomain(p1, p2)`` -- Check if domains match 

102- ``Poly.has_sametype(p1, p2)`` -- Check if types match 

103- ``Poly.has_samewindow(p1, p2)`` -- Check if windows match 

104 

105Misc 

106---- 

107- ``p.linspace()`` -- Return ``x, p(x)`` at equally-spaced points in ``domain`` 

108- ``p.mapparms()`` -- Return the parameters for the linear mapping between 

109 ``domain`` and ``window``. 

110- ``p.roots()`` -- Return the roots of `p`. 

111- ``p.trim()`` -- Remove trailing coefficients. 

112- ``p.cutdeg(degree)`` -- Truncate p to given degree 

113- ``p.truncate(size)`` -- Truncate p to given size 

114 

115""" 

116from .polynomial import Polynomial 

117from .chebyshev import Chebyshev 

118from .legendre import Legendre 

119from .hermite import Hermite 

120from .hermite_e import HermiteE 

121from .laguerre import Laguerre 

122 

123__all__ = [ 

124 "set_default_printstyle", 

125 "polynomial", "Polynomial", 

126 "chebyshev", "Chebyshev", 

127 "legendre", "Legendre", 

128 "hermite", "Hermite", 

129 "hermite_e", "HermiteE", 

130 "laguerre", "Laguerre", 

131] 

132 

133 

134def set_default_printstyle(style): 

135 """ 

136 Set the default format for the string representation of polynomials. 

137 

138 Values for ``style`` must be valid inputs to ``__format__``, i.e. 'ascii' 

139 or 'unicode'. 

140 

141 Parameters 

142 ---------- 

143 style : str 

144 Format string for default printing style. Must be either 'ascii' or 

145 'unicode'. 

146 

147 Notes 

148 ----- 

149 The default format depends on the platform: 'unicode' is used on 

150 Unix-based systems and 'ascii' on Windows. This determination is based on 

151 default font support for the unicode superscript and subscript ranges. 

152 

153 Examples 

154 -------- 

155 >>> p = np.polynomial.Polynomial([1, 2, 3]) 

156 >>> c = np.polynomial.Chebyshev([1, 2, 3]) 

157 >>> np.polynomial.set_default_printstyle('unicode') 

158 >>> print(p) 

159 1.0 + 2.0·x¹ + 3.0·x² 

160 >>> print(c) 

161 1.0 + 2.0·T₁(x) + 3.0·T₂(x) 

162 >>> np.polynomial.set_default_printstyle('ascii') 

163 >>> print(p) 

164 1.0 + 2.0 x**1 + 3.0 x**2 

165 >>> print(c) 

166 1.0 + 2.0 T_1(x) + 3.0 T_2(x) 

167 >>> # Formatting supersedes all class/package-level defaults 

168 >>> print(f"{p:unicode}") 

169 1.0 + 2.0·x¹ + 3.0·x² 

170 """ 

171 if style not in ('unicode', 'ascii'): 

172 raise ValueError( 

173 f"Unsupported format string '{style}'. Valid options are 'ascii' " 

174 f"and 'unicode'" 

175 ) 

176 _use_unicode = True 

177 if style == 'ascii': 

178 _use_unicode = False 

179 from ._polybase import ABCPolyBase 

180 ABCPolyBase._use_unicode = _use_unicode 

181 

182 

183from numpy._pytesttester import PytestTester 

184test = PytestTester(__name__) 

185del PytestTester