Module: sage.modules.real_double_vector
Real double vectors
Author Log:
TESTS:
sage: v = vector(RDF, [1,2,3,4]) sage: loads(dumps(v)) == v True
Module-level Functions
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Class: RealDoubleVectorSpaceElement
Functions: change_ring,
complex_vector,
fft,
mean,
n,
numpy,
prod,
standard_deviation,
stats_kurtosis,
stats_lag1_autocorrelation,
stats_skew,
sum,
variance
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sage: v = vector(RDF,4,range(4)); v (0.0, 1.0, 2.0, 3.0) sage: v.change_ring(CC) (0, 1.00000000000000, 2.00000000000000, 3.00000000000000) sage: v.change_ring(CDF) (0, 1.0, 2.0, 3.0) sage: v.change_ring(RR) (0.000000000000000, 1.00000000000000, 2.00000000000000, 3.00000000000000) sage: v = vector(RDF,0) sage: v.change_ring(CC) ()
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Return the associated complex vector, i.e., this vector but with coefficients viewed as complex numbers.
sage: v = vector(RDF,4,range(4)); v (0.0, 1.0, 2.0, 3.0) sage: v.complex_vector() (0, 1.0, 2.0, 3.0) sage: v = vector(RDF,0) sage: v.complex_vector() ()
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Return the fast Fourier transform of this vector over the complex numbers.
Input:
sage: v = vector(RDF,4,range(4)); v (0.0, 1.0, 2.0, 3.0) sage: v.fft() (6.0, -2.0 + 2.0*I, -2.0, -2.0 - 2.0*I) sage: v.fft(direction='backward') (1.5, -0.5 - 0.5*I, -0.5, -0.5 + 0.5*I) sage: v.fft(direction='backward').fft() # random low order bits (0, 1.0 - 5.74627151417e-18*I, 2.0, 3.0 + 5.74627151417e-18*I)
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Returns a numerical approximation of self by calling the n() method on all of its entries.
sage: v = vector(RDF, [1,2,3]) sage: v.n() (1.00000000000000, 2.00000000000000, 3.00000000000000) sage: _.parent() Vector space of dimension 3 over Real Field with 53 bits of precision sage: v.n(prec=75) (1.000000000000000000000, 2.000000000000000000000, 3.000000000000000000000) sage: _.parent() Vector space of dimension 3 over Real Field with 75 bits of precision
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Return numpy array corresponding to this vector.
sage: v = vector(RDF,4,range(4)) sage: v.numpy() array([ 0., 1., 2., 3.]) sage: v = vector(RDF,0) sage: v.numpy() array([], shape=(1, 0), dtype=float64)
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Return the product of the entries of self.
Output: RealDoubleElement
sage: v = vector(RDF,[1,2,3,-5]) sage: v.prod() -30.0
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sage: v = vector(RDF, 5, [1,2,3,4,5]) sage: v.standard_deviation() 1.5811388300841898
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Return the sum of the entries of self.
Output: RealDoubleElement
sage: v = vector(RDF,[1,2,3,-5]) sage: v.sum() 1.0
Special Functions: __copy__,
__delitem__,
__getitem__,
__init__,
__len__,
__reduce__,
__setitem__,
_replace_self_with_numpy
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Return the ith entry of self.
sage: v = vector(RDF, [1, sqrt(2), -1]); v (1.0, 1.41421356237, -1.0) sage: a = v[1]; a 1.41421356237 sage: v[-2] 1.41421356237 sage: parent(a) Real Double Field sage: v[5] Traceback (most recent call last): ... IndexError: index out of range sage: v[-5] Traceback (most recent call last): ... IndexError: index out of range
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