NumPy参考 >例行程序 >Polynomials >Polynomial Package >拉盖尔模块(numpy.polynomial.laguerre) > numpy.polynomial.laguerre.lagtrim
numpy.polynomial.laguerre.
lagtrim
(c, tol=0)[source]¶Remove “small” “trailing” coefficients from a polynomial.
“Small” means “small in absolute value” and is controlled by the
parameter tol; “trailing” means highest order coefficient(s), e.g., in
[0, 1, 1, 0, 0]
(which represents 0 + x + x**2 + 0*x**3 + 0*x**4
)
both the 3-rd and 4-th order coefficients would be “trimmed.”
1-d array of coefficients, ordered from lowest order to highest.
Trailing (i.e., highest order) elements with absolute value less than or equal to tol (default value is zero) are removed.
1-d array with trailing zeros removed. If the resulting series would be empty, a series containing a single zero is returned.
If tol < 0
See also
trimseq
Examples
>>> from numpy.polynomial import polyutils as pu
>>> pu.trimcoef((0,0,3,0,5,0,0))
array([0., 0., 3., 0., 5.])
>>> pu.trimcoef((0,0,1e-3,0,1e-5,0,0),1e-3) # item == tol is trimmed
array([0.])
>>> i = complex(0,1) # works for complex
>>> pu.trimcoef((3e-4,1e-3*(1-i),5e-4,2e-5*(1+i)), 1e-3)
array([0.0003+0.j , 0.001 -0.001j])