def test_PDF(): a = Symbol('a', positive=True) x = Symbol('x', real=True) exponential = PDF(exp(-x / a), (x, 0, oo)) exponential = exponential.normalize() assert exponential.pdf(x) == 1 / a * exp(-x / a) assert exponential.cdf(x) == 1 - exp(-x / a) assert exponential.mean == a assert exponential.variance == a**2 assert exponential.stddev == a
def test_PDF(): a = Symbol('a', positive=True) x = Symbol('x', real=True) exponential = PDF(exp(-x/a), (x,0,oo)) exponential = exponential.normalize() assert exponential.pdf(x) == 1/a*exp(-x/a) assert exponential.cdf(x) == 1 - exp(-x/a) assert exponential.mean == a assert exponential.variance == a**2 assert exponential.stddev == a
def test_PDF(): a = Symbol('a', positive=True) x = Symbol('x', real=True) exponential = PDF(exp(-x/a), (x, 0, oo)) exponential = exponential.normalize() assert exponential.pdf(x) == 1/a*exp(-x/a) assert exponential.cdf(x) == 1 - exp(-x/a) assert exponential.mean == a assert exponential.variance == a**2 assert exponential.stddev == a exponential = PDF(exp(-x/a), x) assert exponential.pdf(x) == exp(-x/a) assert exponential.cdf(x) == -a*exp(-x/a) + oo assert exponential.mean == -oo exponential = PDF(1, (x, 1, 2)) assert exponential.normalize() == exponential assert exponential._get_stddev() == sqrt(3)/6 assert exponential._get_stddev() == sqrt(3)/6 #This test is intentionally repeated to test PDF._get_stddev() properly. exponential = exponential.transform(x, x) assert exponential.pdf(x) == 1 assert exponential.cdf(x) == x - 1
def test_PDF(): a = Symbol('a', positive=True) x = Symbol('x', real=True) exponential = PDF(exp(-x / a), (x, 0, oo)) exponential = exponential.normalize() assert exponential.pdf(x) == 1 / a * exp(-x / a) assert exponential.cdf(x) == 1 - exp(-x / a) assert exponential.mean == a assert exponential.variance == a**2 assert exponential.stddev == a exponential = PDF(exp(-x / a), x) assert exponential.pdf(x) == exp(-x / a) assert exponential.cdf(x) == -a * exp(-x / a) + oo assert exponential.mean == -oo exponential = PDF(1, (x, 1, 2)) assert exponential.normalize() == exponential assert exponential._get_stddev() == sqrt(3) / 6 assert exponential._get_stddev() == sqrt(3) / 6 #This test is intentionally repeated to test PDF._get_stddev() properly. exponential = exponential.transform(x, x) assert exponential.pdf(x) == 1 assert exponential.cdf(x) == x - 1