diff options
Diffstat (limited to 'numpy')
| -rw-r--r-- | numpy/polynomial/polytemplate.py | 35 | ||||
| -rw-r--r-- | numpy/polynomial/tests/test_chebyshev.py | 8 | ||||
| -rw-r--r-- | numpy/polynomial/tests/test_polynomial.py | 8 |
3 files changed, 50 insertions, 1 deletions
diff --git a/numpy/polynomial/polytemplate.py b/numpy/polynomial/polytemplate.py index bf94d28ec..706f22c2d 100644 --- a/numpy/polynomial/polytemplate.py +++ b/numpy/polynomial/polytemplate.py @@ -304,9 +304,42 @@ class $name(pu.PolyBase) : # def degree(self) : - """The degree of the series.""" + """The degree of the series. + + Notes + ----- + .. versionadded:: 2.0.0 + + """ return len(self) - 1 + def reduce(self, deg) : + """Reduce the degree of the series. + + Reduce the degree of the $name series to `deg` by discarding the + high order terms. If `deg` is greater than the current degree a + copy of the current series is returned. 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 high + order terms. The value of `deg` must be a non-negative integer. + + Returns: + ------- + new_instance : $name + New instance of $name with reduced degree. + + Notes + ----- + .. versionadded:: 2.0.0 + + """ + return self.truncate(deg + 1) + def convert(self, domain=None, kind=None) : """Convert to different class and/or domain. diff --git a/numpy/polynomial/tests/test_chebyshev.py b/numpy/polynomial/tests/test_chebyshev.py index d61e8b07c..5662d0362 100644 --- a/numpy/polynomial/tests/test_chebyshev.py +++ b/numpy/polynomial/tests/test_chebyshev.py @@ -402,6 +402,14 @@ class TestChebyshevClass(TestCase) : def test_degree(self) : assert_equal(self.p1.degree(), 2) + def test_reduce(self) : + assert_raises(ValueError, self.p1.reduce, .5) + assert_raises(ValueError, self.p1.reduce, -1) + assert_equal(len(self.p1.reduce(3)), 3) + assert_equal(len(self.p1.reduce(2)), 3) + assert_equal(len(self.p1.reduce(1)), 2) + assert_equal(len(self.p1.reduce(0)), 1) + def test_convert(self) : x = np.linspace(-1,1) p = self.p1.convert(domain=[0,1]) diff --git a/numpy/polynomial/tests/test_polynomial.py b/numpy/polynomial/tests/test_polynomial.py index 530e5d949..15525fcd8 100644 --- a/numpy/polynomial/tests/test_polynomial.py +++ b/numpy/polynomial/tests/test_polynomial.py @@ -373,6 +373,14 @@ class TestPolynomialClass(TestCase) : def test_degree(self) : assert_equal(self.p1.degree(), 2) + def test_reduce(self) : + assert_raises(ValueError, self.p1.reduce, .5) + assert_raises(ValueError, self.p1.reduce, -1) + assert_equal(len(self.p1.reduce(3)), 3) + assert_equal(len(self.p1.reduce(2)), 3) + assert_equal(len(self.p1.reduce(1)), 2) + assert_equal(len(self.p1.reduce(0)), 1) + def test_convert(self) : x = np.linspace(-1,1) p = self.p1.convert(domain=[0,1]) |