diff options
| -rw-r--r-- | doc/release/2.0.0-notes.rst | 6 | ||||
| -rw-r--r-- | numpy/polynomial/polytemplate.py | 37 | ||||
| -rw-r--r-- | numpy/polynomial/tests/test_chebyshev.py | 8 | ||||
| -rw-r--r-- | numpy/polynomial/tests/test_polynomial.py | 8 |
4 files changed, 26 insertions, 33 deletions
diff --git a/doc/release/2.0.0-notes.rst b/doc/release/2.0.0-notes.rst index 85f15c38f..fc2faac2e 100644 --- a/doc/release/2.0.0-notes.rst +++ b/doc/release/2.0.0-notes.rst @@ -77,9 +77,6 @@ polynomial.polynomial derivations is a non-negative integer. The number 0 is a valid value for both functions. * A degree method has been added to the Polynomial class. -* The truncate method of the Polynomial class now takes the degree of the - desired result as an argument instead of the number of coefficients. This - seems more natural. * The fit class function of the Polynomial class now uses None as the default domain for the fit. The domain can be specified as 'default' to use the Polynomial default domain [-1, 1]. @@ -91,9 +88,6 @@ polynomial.chebyshev derivations is a non-negative integer. The number 0 is a valid value for both functions. * A degree method has been added to the Chebyshev class. -* The truncate method of the Chebyshev class now takes the degree of the - desired result as an argument instead of the number of coefficients. This - seems more natural. * The fit class function of the Chebyshev class now uses None as the default domain for the fit. The domain can be specified as 'default' to use the Chebyshev default domain [-1, 1]. diff --git a/numpy/polynomial/polytemplate.py b/numpy/polynomial/polytemplate.py index 08510c1ff..bf94d28ec 100644 --- a/numpy/polynomial/polytemplate.py +++ b/numpy/polynomial/polytemplate.py @@ -391,20 +391,19 @@ class $name(pu.PolyBase) : """ return self.__class__(pu.trimcoef(self.coef, tol), self.domain) - def truncate(self, deg) : - """Truncate series to degree `deg`. + def truncate(self, size) : + """Truncate series to length `size`. - Return a $name series obtained from the current instance by discarding - all terms of degree greater than `deg`. The value of `deg` must be - non-negative. This operation is most likely to be useful in least squares - fits when the high order coefficients are very small. + Reduce the $name series to length `size` by discarding the high + degree terms. The value of `size` must be a positive integer. This + can be useful in least squares where the coefficients of the + high degree terms may be very small. Parameters: ----------- - deg : non-negative int - The series is reduced to degree `deg` by discarding the - coefficients of the higher degree terms. The value of `deg` - must be non-negative. + size : positive int + The series is reduced to length `size` by discarding the high + degree terms. The value of `size` must be a positive integer. Returns: ------- @@ -412,13 +411,13 @@ class $name(pu.PolyBase) : New instance of $name with truncated coefficients. """ - size = int(deg) + 1 - if size != deg + 1 or size < 1 : - raise ValueError("deg must be a non-negative integer") - if size >= len(self) : + isize = int(size) + if isize != size or isize < 1 : + raise ValueError("size must be a positive integer") + if isize >= len(self.coef) : return self.__class__(self.coef, self.domain) else : - return self.__class__(self.coef[:size], self.domain) + return self.__class__(self.coef[:isize], self.domain) def copy(self) : """Return a copy. @@ -442,7 +441,7 @@ class $name(pu.PolyBase) : Parameters: ----------- - m : non-negative integer + m : non-negative int The number of integrations to perform. k : array_like Integration constants. The first constant is applied to the @@ -455,7 +454,7 @@ class $name(pu.PolyBase) : Returns: -------- integral : $name - The integral of the original series with the same domain. + The integral of the series using the same domain. See Also -------- @@ -479,13 +478,13 @@ class $name(pu.PolyBase) : Parameters: ----------- - m : non-negative integer + m : non-negative int The number of integrations to perform. Returns: -------- derivative : $name - The derivative of the original series with the same domain. + The derivative of the series using the same domain. See Also -------- diff --git a/numpy/polynomial/tests/test_chebyshev.py b/numpy/polynomial/tests/test_chebyshev.py index 2278ca871..d61e8b07c 100644 --- a/numpy/polynomial/tests/test_chebyshev.py +++ b/numpy/polynomial/tests/test_chebyshev.py @@ -420,11 +420,11 @@ class TestChebyshevClass(TestCase) : def test_truncate(self) : assert_raises(ValueError, self.p1.truncate, .5) - assert_raises(ValueError, self.p1.truncate, -1) + assert_raises(ValueError, self.p1.truncate, 0) + assert_equal(len(self.p1.truncate(4)), 3) assert_equal(len(self.p1.truncate(3)), 3) - assert_equal(len(self.p1.truncate(2)), 3) - assert_equal(len(self.p1.truncate(1)), 2) - assert_equal(len(self.p1.truncate(0)), 1) + assert_equal(len(self.p1.truncate(2)), 2) + assert_equal(len(self.p1.truncate(1)), 1) def test_copy(self) : p = self.p1.copy() diff --git a/numpy/polynomial/tests/test_polynomial.py b/numpy/polynomial/tests/test_polynomial.py index 13718fe9e..530e5d949 100644 --- a/numpy/polynomial/tests/test_polynomial.py +++ b/numpy/polynomial/tests/test_polynomial.py @@ -391,11 +391,11 @@ class TestPolynomialClass(TestCase) : def test_truncate(self) : assert_raises(ValueError, self.p1.truncate, .5) - assert_raises(ValueError, self.p1.truncate, -1) + assert_raises(ValueError, self.p1.truncate, 0) + assert_equal(len(self.p1.truncate(4)), 3) assert_equal(len(self.p1.truncate(3)), 3) - assert_equal(len(self.p1.truncate(2)), 3) - assert_equal(len(self.p1.truncate(1)), 2) - assert_equal(len(self.p1.truncate(0)), 1) + assert_equal(len(self.p1.truncate(2)), 2) + assert_equal(len(self.p1.truncate(1)), 1) def test_copy(self) : p = self.p1.copy() |