def test_derivative_numerically(f, z, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that the symbolically computed derivative of f
with respect to z is correct.
Examples
========
>>> from sympy import sin, cos
>>> from sympy.abc import x
>>> from sympy.utilities.randtest import test_derivative_numerically as td
>>> td(sin(x), x)
True
"""
from sympy.core.function import Derivative
z0 = random_complex_number(a, b, c, d)
f1 = f.diff(z).subs(z, z0)
f2 = Derivative(f, z).doit_numerically(z0)
return comp(f1.n(), f2.n(), tol)
def test_derivative_numerically(f, z, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that the symbolically computed derivative of f
with respect to z is correct.
This routine does not test whether there are Floats present with
precision higher than 15 digits so if there are, your results may
not be what you expect due to round-off errors.
Examples
========
>>> from sympy import sin, cos
>>> from sympy.abc import x
>>> from sympy.utilities.randtest import test_derivative_numerically as td
>>> td(sin(x), x)
True
"""
from sympy.core.function import Derivative
z0 = random_complex_number(a, b, c, d)
f1 = f.diff(z).subs(z, z0)
f2 = Derivative(f, z).doit_numerically(z0)
return comp(f1.n(), f2.n(), tol)
def _eval_derivative(self, x):
if x.is_real or self.args[0].is_real:
return re(Derivative(self.args[0], x, evaluate=True))
if x.is_imaginary or self.args[0].is_imaginary:
return -S.ImaginaryUnit \
* im(Derivative(self.args[0], x, evaluate=True))
def _eval_derivative(self, t):
x, y = re(self.args[0]), im(self.args[0])
return (x * Derivative(y, t, evaluate=True) -
y * Derivative(x, t, evaluate=True)) / (x**2 + y**2)
def test_del_operator():
# Tests for curl
assert delop ^ Vector.zero == Vector.zero
assert (delop ^ Vector.zero).doit() == Vector.zero == curl(Vector.zero)
assert delop.cross(Vector.zero) == delop ^ Vector.zero
assert (delop ^ i).doit() == Vector.zero
assert delop.cross(2 * y ** 2 * j, doit=True) == Vector.zero
assert delop.cross(2 * y ** 2 * j) == delop ^ 2 * y ** 2 * j
v = x * y * z * (i + j + k)
assert (
(delop ^ v).doit()
== (-x * y + x * z) * i + (x * y - y * z) * j + (-x * z + y * z) * k
== curl(v)
)
assert delop ^ v == delop.cross(v)
assert (
delop.cross(2 * x ** 2 * j)
== (Derivative(0, C.y) - Derivative(2 * C.x ** 2, C.z)) * C.i
+ (-Derivative(0, C.x) + Derivative(0, C.z)) * C.j
+ (-Derivative(0, C.y) + Derivative(2 * C.x ** 2, C.x)) * C.k
)
assert delop.cross(2 * x ** 2 * j, doit=True) == 4 * x * k == curl(2 * x ** 2 * j)
# Tests for divergence
assert delop & Vector.zero is S.Zero == divergence(Vector.zero)
assert (delop & Vector.zero).doit() is S.Zero
assert delop.dot(Vector.zero) == delop & Vector.zero
assert (delop & i).doit() is S.Zero
assert (delop & x ** 2 * i).doit() == 2 * x == divergence(x ** 2 * i)
assert delop.dot(v, doit=True) == x * y + y * z + z * x == divergence(v)
assert delop & v == delop.dot(v)
assert delop.dot(1 / (x * y * z) * (i + j + k), doit=True) == -1 / (
x * y * z ** 2
) - 1 / (x * y ** 2 * z) - 1 / (x ** 2 * y * z)
v = x * i + y * j + z * k
assert delop & v == Derivative(C.x, C.x) + Derivative(C.y, C.y) + Derivative(
C.z, C.z
)
assert delop.dot(v, doit=True) == 3 == divergence(v)
assert delop & v == delop.dot(v)
assert simplify((delop & v).doit()) == 3
# Tests for gradient
assert delop.gradient(0, doit=True) == Vector.zero == gradient(0)
assert delop.gradient(0) == delop(0)
assert (delop(S.Zero)).doit() == Vector.zero
assert (
delop(x)
== (Derivative(C.x, C.x)) * C.i
+ (Derivative(C.x, C.y)) * C.j
+ (Derivative(C.x, C.z)) * C.k
)
assert (delop(x)).doit() == i == gradient(x)
assert (
delop(x * y * z)
== (Derivative(C.x * C.y * C.z, C.x)) * C.i
+ (Derivative(C.x * C.y * C.z, C.y)) * C.j
+ (Derivative(C.x * C.y * C.z, C.z)) * C.k
)
assert (
delop.gradient(x * y * z, doit=True)
== y * z * i + z * x * j + x * y * k
== gradient(x * y * z)
)
assert delop(x * y * z) == delop.gradient(x * y * z)
assert (delop(2 * x ** 2)).doit() == 4 * x * i
assert (delop(a * sin(y) / x)).doit() == -a * sin(y) / x ** 2 * i + a * cos(
y
) / x * j
# Tests for directional derivative
assert (Vector.zero & delop)(a) is S.Zero
assert ((Vector.zero & delop)(a)).doit() is S.Zero
assert ((v & delop)(Vector.zero)).doit() == Vector.zero
assert ((v & delop)(S.Zero)).doit() is S.Zero
assert ((i & delop)(x)).doit() == 1
assert ((j & delop)(y)).doit() == 1
assert ((k & delop)(z)).doit() == 1
assert ((i & delop)(x * y * z)).doit() == y * z
assert ((v & delop)(x)).doit() == x
assert ((v & delop)(x * y * z)).doit() == 3 * x * y * z
assert (v & delop)(x + y + z) == C.x + C.y + C.z
assert ((v & delop)(x + y + z)).doit() == x + y + z
assert ((v & delop)(v)).doit() == v
assert ((i & delop)(v)).doit() == i
assert ((j & delop)(v)).doit() == j
assert ((k & delop)(v)).doit() == k
assert ((v & delop)(Vector.zero)).doit() == Vector.zero
# Tests for laplacian on scalar fields
assert laplacian(x * y * z) is S.Zero
assert laplacian(x ** 2) == S(2)
assert (
laplacian(x ** 2 * y ** 2 * z ** 2)
== 2 * y ** 2 * z ** 2 + 2 * x ** 2 * z ** 2 + 2 * x ** 2 * y ** 2
)
A = CoordSys3D(
"A", transformation="spherical", variable_names=["r", "theta", "phi"]
)
B = CoordSys3D(
"B", transformation="cylindrical", variable_names=["r", "theta", "z"]
)
assert laplacian(A.r + A.theta + A.phi) == 2 / A.r + cos(A.theta) / (
A.r ** 2 * sin(A.theta)
)
assert laplacian(B.r + B.theta + B.z) == 1 / B.r
# Tests for laplacian on vector fields
assert laplacian(x * y * z * (i + j + k)) == Vector.zero
assert (
laplacian(x * y ** 2 * z * (i + j + k))
== 2 * x * z * i + 2 * x * z * j + 2 * x * z * k
)
def test_Function():
assert precedence(sin(x)) == PRECEDENCE["Atom"]
assert precedence(Derivative(x, y)) == PRECEDENCE["Atom"]
def _eval_derivative(self, x):
return re(Derivative(self.args[0], x, **{'evaluate': True}))
def test_core_function():
x = Symbol("x")
for f in (Derivative, Derivative(x), Function, FunctionClass, Lambda,\
WildFunction):
check(f)
def test_jacobi():
n = Symbol("n")
a = Symbol("a")
b = Symbol("b")
assert jacobi(0, a, b, x) == 1
assert jacobi(1, a, b, x) == a / 2 - b / 2 + x * (a / 2 + b / 2 + 1)
assert jacobi(n, a, a, x) == RisingFactorial(a + 1, n) * gegenbauer(
n, a + S.Half, x) / RisingFactorial(2 * a + 1, n)
assert jacobi(n, a, -a,
x) == ((-1)**a * (-x + 1)**(-a / 2) * (x + 1)**(a / 2) *
assoc_legendre(n, a, x) * factorial(-a + n) *
gamma(a + n + 1) / (factorial(a + n) * gamma(n + 1)))
assert jacobi(n, -b, b, x) == ((-x + 1)**(b / 2) * (x + 1)**(-b / 2) *
assoc_legendre(n, b, x) *
gamma(-b + n + 1) / gamma(n + 1))
assert jacobi(n, 0, 0, x) == legendre(n, x)
assert jacobi(n, S.Half, S.Half, x) == RisingFactorial(Rational(
3, 2), n) * chebyshevu(n, x) / factorial(n + 1)
assert jacobi(
n, Rational(-1, 2), Rational(-1, 2),
x) == RisingFactorial(S.Half, n) * chebyshevt(n, x) / factorial(n)
X = jacobi(n, a, b, x)
assert isinstance(X, jacobi)
assert jacobi(n, a, b, -x) == (-1)**n * jacobi(n, b, a, x)
assert jacobi(n, a, b, 0) == 2**(-n) * gamma(a + n + 1) * hyper(
(-b - n, -n), (a + 1, ), -1) / (factorial(n) * gamma(a + 1))
assert jacobi(n, a, b, 1) == RisingFactorial(a + 1, n) / factorial(n)
m = Symbol("m", positive=True)
assert jacobi(m, a, b, oo) == oo * RisingFactorial(a + b + m + 1, m)
assert unchanged(jacobi, n, a, b, oo)
assert conjugate(jacobi(m, a, b, x)) == \
jacobi(m, conjugate(a), conjugate(b), conjugate(x))
_k = Dummy('k')
assert diff(jacobi(n, a, b, x), n) == Derivative(jacobi(n, a, b, x), n)
assert diff(jacobi(n, a, b, x), a).dummy_eq(
Sum((jacobi(n, a, b, x) + (2 * _k + a + b + 1) *
RisingFactorial(_k + b + 1, -_k + n) * jacobi(_k, a, b, x) /
((-_k + n) * RisingFactorial(_k + a + b + 1, -_k + n))) /
(_k + a + b + n + 1), (_k, 0, n - 1)))
assert diff(jacobi(n, a, b, x), b).dummy_eq(
Sum(((-1)**(-_k + n) * (2 * _k + a + b + 1) *
RisingFactorial(_k + a + 1, -_k + n) * jacobi(_k, a, b, x) /
((-_k + n) * RisingFactorial(_k + a + b + 1, -_k + n)) +
jacobi(n, a, b, x)) / (_k + a + b + n + 1), (_k, 0, n - 1)))
assert diff(jacobi(n, a, b, x), x) == \
(a/2 + b/2 + n/2 + S.Half)*jacobi(n - 1, a + 1, b + 1, x)
assert jacobi_normalized(n, a, b, x) == \
(jacobi(n, a, b, x)/sqrt(2**(a + b + 1)*gamma(a + n + 1)*gamma(b + n + 1)
/((a + b + 2*n + 1)*factorial(n)*gamma(a + b + n + 1))))
raises(ValueError, lambda: jacobi(-2.1, a, b, x))
raises(ValueError,
lambda: jacobi(Dummy(positive=True, integer=True), 1, 2, oo))
assert jacobi(n, a, b, x).rewrite("polynomial").dummy_eq(
Sum((S.Half - x / 2)**_k * RisingFactorial(-n, _k) *
RisingFactorial(_k + a + 1, -_k + n) *
RisingFactorial(a + b + n + 1, _k) / factorial(_k),
(_k, 0, n)) / factorial(n))
raises(ArgumentIndexError, lambda: jacobi(n, a, b, x).fdiff(5))
def _as_finite_diff(derivative, points=1, x0=None, wrt=None):
"""
Returns an approximation of a derivative of a function in
the form of a finite difference formula. The expression is a
weighted sum of the function at a number of discrete values of
(one of) the independent variable(s).
Parameters
==========
derivative: a Derivative instance
points: sequence or coefficient, optional
If sequence: discrete values (length >= order+1) of the
independent variable used for generating the finite
difference weights.
If it is a coefficient, it will be used as the step-size
for generating an equidistant sequence of length order+1
centered around ``x0``. default: 1 (step-size 1)
x0: number or Symbol, optional
the value of the independent variable (``wrt``) at which the
derivative is to be approximated. Default: same as ``wrt``.
wrt: Symbol, optional
"with respect to" the variable for which the (partial)
derivative is to be approximated for. If not provided it
is required that the Derivative is ordinary. Default: ``None``.
Examples
========
>>> from sympy import symbols, Function, exp, sqrt, Symbol, as_finite_diff
>>> from sympy.utilities.exceptions import SymPyDeprecationWarning
>>> import warnings
>>> warnings.simplefilter("ignore", SymPyDeprecationWarning)
>>> x, h = symbols('x h')
>>> f = Function('f')
>>> as_finite_diff(f(x).diff(x))
-f(x - 1/2) + f(x + 1/2)
The default step size and number of points are 1 and ``order + 1``
respectively. We can change the step size by passing a symbol
as a parameter:
>>> as_finite_diff(f(x).diff(x), h)
-f(-h/2 + x)/h + f(h/2 + x)/h
We can also specify the discretized values to be used in a sequence:
>>> as_finite_diff(f(x).diff(x), [x, x+h, x+2*h])
-3*f(x)/(2*h) + 2*f(h + x)/h - f(2*h + x)/(2*h)
The algorithm is not restricted to use equidistant spacing, nor
do we need to make the approximation around ``x0``, but we can get
an expression estimating the derivative at an offset:
>>> e, sq2 = exp(1), sqrt(2)
>>> xl = [x-h, x+h, x+e*h]
>>> as_finite_diff(f(x).diff(x, 1), xl, x+h*sq2)
2*h*((h + sqrt(2)*h)/(2*h) - (-sqrt(2)*h + h)/(2*h))*f(E*h + x)/((-h + E*h)*(h + E*h)) +
(-(-sqrt(2)*h + h)/(2*h) - (-sqrt(2)*h + E*h)/(2*h))*f(-h + x)/(h + E*h) +
(-(h + sqrt(2)*h)/(2*h) + (-sqrt(2)*h + E*h)/(2*h))*f(h + x)/(-h + E*h)
Partial derivatives are also supported:
>>> y = Symbol('y')
>>> d2fdxdy=f(x,y).diff(x,y)
>>> as_finite_diff(d2fdxdy, wrt=x)
-Derivative(f(x - 1/2, y), y) + Derivative(f(x + 1/2, y), y)
See also
========
sympy.calculus.finite_diff.apply_finite_diff
sympy.calculus.finite_diff.finite_diff_weights
"""
if derivative.is_Derivative:
pass
elif derivative.is_Atom:
return derivative
else:
return derivative.fromiter(
[_as_finite_diff(ar, points, x0, wrt) for ar
in derivative.args], **derivative.assumptions0)
if wrt is None:
old = None
for v in derivative.variables:
if old is v:
continue
derivative = _as_finite_diff(derivative, points, x0, v)
old = v
return derivative
order = derivative.variables.count(wrt)
if x0 is None:
x0 = wrt
if not iterable(points):
if getattr(points, 'is_Function', False) and wrt in points.args:
points = points.subs(wrt, x0)
# points is simply the step-size, let's make it a
# equidistant sequence centered around x0
if order % 2 == 0:
# even order => odd number of points, grid point included
points = [x0 + points*i for i
in range(-order//2, order//2 + 1)]
else:
# odd order => even number of points, half-way wrt grid point
points = [x0 + points*S(i)/2 for i
in range(-order, order + 1, 2)]
others = [wrt, 0]
for v in set(derivative.variables):
if v == wrt:
continue
others += [v, derivative.variables.count(v)]
if len(points) < order+1:
raise ValueError("Too few points for order %d" % order)
return apply_finite_diff(order, points, [
Derivative(derivative.expr.subs({wrt: x}), *others) for
x in points], x0)
"\\frac{d}{d x}( \\frac{f{\\left(x \\right)}}{g{\left(x \\right)}})")
expresion = expresion.replace(
"\\frac{- f{\\left(x \\right)} \\frac{d}{d x} g{\\left(x \\right)} + g{\\left(x \\right)} \\frac{d}{d x} f{\\left(x \\right)}}{g^{2}{\\left(x \\right)}}",
"\\frac{- f{\\left(x \\right)} \\frac{d}{d x}( g{\\left(x \\right)}) + g{\\left(x \\right)} \\frac{d}{d x}( f{\\left(x \\right))}}{g^{2}{\\left(x \\right)}}")
expresion = expresion.replace("\\frac{d}{d x} f{\\left(x \\right)}",
"\\frac{d}{d x}( f{\\left(x \\right)})")
expresion = expresion.replace("\\frac{d}{d x} g{\\left(x \\right)}",
"\\frac{d}{d x}( g{\\left(x \\right)})")
return expresion
##MAIN##
salida = open("/tmp/solucion_28d36c18-7985-42e7-bce1-11babf379715.txt","w")
x = symbols('x')
expr = parse_latex(r"2x^3+12x^2-30x-1").subs({Symbol('pi'): pi})
salida.write("Obtener: $$%s$$<br><br>" % latex(Derivative(expr, x)))
solucion = print_html_steps(expr, x)
solucion = acomodaNotacion(solucion)
salida.write(solucion)
derivada = Derivative(expr)
derivada = derivada.doit()
anula = solve(derivada, x)
puntos = []
xmin,xmax = 0,0
ymin,ymax = 0,0
solucion = "Resolviendo $$%s=0$$ obtenemos las raices<br/>" % (latex(derivada))
n = 1
for x_0 in anula:
solucion = solucion + "$$x_%s=%s$$ <br/>" % (n, latex(x_0))
n = n+1
n = 1
def _eval_diff(self, *args, **kwargs):
if kwargs.pop("evaluate", True):
return self.diff(*args)
else:
return Derivative(self, *args, **kwargs)
def _eval_derivative(self, x):
if not self.has(x):
return S.Zero
return re(Derivative(self.args[0], x, **{'evaluate': True}))
def _eval_derivative(self, t):
x, y = re(self.args[0]), im(self.args[0])
if not self.has(t):
return S.Zero
return (x * Derivative(y, t, **{'evaluate': True}) - y *
Derivative(x, t, **{'evaluate': True})) / (x**2 + y**2)
def test_count_ops_visual():
ADD, MUL, POW, SIN, COS, EXP, AND, D, G, M = symbols(
'Add Mul Pow sin cos exp And Derivative Integral Sum'.upper())
DIV, SUB, NEG = symbols('DIV SUB NEG')
LT, LE, GT, GE, EQ, NE = symbols('LT LE GT GE EQ NE')
NOT, OR, AND, XOR, IMPLIES, EQUIVALENT, _ITE, BASIC, TUPLE = symbols(
'Not Or And Xor Implies Equivalent ITE Basic Tuple'.upper())
def count(val):
return count_ops(val, visual=True)
assert count(7) is S.Zero
assert count(S(7)) is S.Zero
assert count(-1) == NEG
assert count(-2) == NEG
assert count(S(2) / 3) == DIV
assert count(Rational(2, 3)) == DIV
assert count(pi / 3) == DIV
assert count(-pi / 3) == DIV + NEG
assert count(I - 1) == SUB
assert count(1 - I) == SUB
assert count(1 - 2 * I) == SUB + MUL
assert count(x) is S.Zero
assert count(-x) == NEG
assert count(-2 * x / 3) == NEG + DIV + MUL
assert count(Rational(-2, 3) * x) == NEG + DIV + MUL
assert count(1 / x) == DIV
assert count(1 / (x * y)) == DIV + MUL
assert count(-1 / x) == NEG + DIV
assert count(-2 / x) == NEG + DIV
assert count(x / y) == DIV
assert count(-x / y) == NEG + DIV
assert count(x**2) == POW
assert count(-x**2) == POW + NEG
assert count(-2 * x**2) == POW + MUL + NEG
assert count(x + pi / 3) == ADD + DIV
assert count(x + S.One / 3) == ADD + DIV
assert count(x + Rational(1, 3)) == ADD + DIV
assert count(x + y) == ADD
assert count(x - y) == SUB
assert count(y - x) == SUB
assert count(-1 / (x - y)) == DIV + NEG + SUB
assert count(-1 / (y - x)) == DIV + NEG + SUB
assert count(1 + x**y) == ADD + POW
assert count(1 + x + y) == 2 * ADD
assert count(1 + x + y + z) == 3 * ADD
assert count(1 + x**y + 2 * x * y + y**2) == 3 * ADD + 2 * POW + 2 * MUL
assert count(2 * z + y + x + 1) == 3 * ADD + MUL
assert count(2 * z + y**17 + x + 1) == 3 * ADD + MUL + POW
assert count(2 * z + y**17 + x + sin(x)) == 3 * ADD + POW + MUL + SIN
assert count(2 * z + y**17 + x +
sin(x**2)) == 3 * ADD + MUL + 2 * POW + SIN
assert count(2 * z + y**17 + x + sin(x**2) +
exp(cos(x))) == 4 * ADD + MUL + 2 * POW + EXP + COS + SIN
assert count(Derivative(x, x)) == D
assert count(Integral(x, x) + 2 * x / (1 + x)) == G + DIV + MUL + 2 * ADD
assert count(Sum(x, (x, 1, x + 1)) + 2 * x /
(1 + x)) == M + DIV + MUL + 3 * ADD
assert count(Basic()) is S.Zero
assert count({x + 1: sin(x)}) == ADD + SIN
assert count([x + 1, sin(x) + y, None]) == ADD + SIN + ADD
assert count({x + 1: sin(x), y: cos(x) + 1}) == SIN + COS + 2 * ADD
assert count({}) is S.Zero
assert count([x + 1, sin(x) * y, None]) == SIN + ADD + MUL
assert count([]) is S.Zero
assert count(Basic()) == 0
assert count(Basic(Basic(), Basic(x, x + y))) == ADD + 2 * BASIC
assert count(Basic(x, x + y)) == ADD + BASIC
assert [count(Rel(x, y, op)) for op in '< <= > >= == <> !='.split()
] == [LT, LE, GT, GE, EQ, NE, NE]
assert count(Or(x, y)) == OR
assert count(And(x, y)) == AND
assert count(Or(x, Or(y, And(z, a)))) == AND + OR
assert count(Nor(x, y)) == NOT + OR
assert count(Nand(x, y)) == NOT + AND
assert count(Xor(x, y)) == XOR
assert count(Implies(x, y)) == IMPLIES
assert count(Equivalent(x, y)) == EQUIVALENT
assert count(ITE(x, y, z)) == _ITE
assert count([Or(x, y), And(x, y), Basic(x + y)]) == ADD + AND + BASIC + OR
assert count(Basic(Tuple(x))) == BASIC + TUPLE
#It checks that TUPLE is counted as an operation.
assert count(Eq(x + y, S(2))) == ADD + EQ
(r"\frac{a}{b}", a / b),
(r"\dfrac{a}{b}", a / b),
(r"\tfrac{a}{b}", a / b),
(r"\frac{a + b}{c}", _Mul(a + b, _Pow(c, -1))),
(r"\frac{7}{3}", _Mul(7, _Pow(3, -1))),
(r"(\csc x)(\sec y)", csc(x) * sec(y)),
(r"\lim_{x \to 3} a", Limit(a, x, 3)),
(r"\lim_{x \rightarrow 3} a", Limit(a, x, 3)),
(r"\lim_{x \Rightarrow 3} a", Limit(a, x, 3)),
(r"\lim_{x \longrightarrow 3} a", Limit(a, x, 3)),
(r"\lim_{x \Longrightarrow 3} a", Limit(a, x, 3)),
(r"\lim_{x \to 3^{+}} a", Limit(a, x, 3, dir='+')),
(r"\lim_{x \to 3^{-}} a", Limit(a, x, 3, dir='-')),
(r"\infty", oo),
(r"\lim_{x \to \infty} \frac{1}{x}", Limit(_Pow(x, -1), x, oo)),
(r"\frac{d}{dx} x", Derivative(x, x)),
(r"\frac{d}{dt} x", Derivative(x, t)),
(r"f(x)", f(x)),
(r"f(x, y)", f(x, y)),
(r"f(x, y, z)", f(x, y, z)),
(r"\frac{d f(x)}{dx}", Derivative(f(x), x)),
(r"\frac{d\theta(x)}{dx}", Derivative(Function('theta')(x), x)),
(r"x \neq y", Unequality(x, y)),
(r"|x|", _Abs(x)),
(r"||x||", _Abs(Abs(x))),
(r"|x||y|", _Abs(x) * _Abs(y)),
(r"||x||y||", _Abs(_Abs(x) * _Abs(y))),
(r"\pi^{|xy|}", Symbol('pi')**_Abs(x * y)),
(r"\int x dx", Integral(x, x)),
(r"\int x d\theta", Integral(x, theta)),
(r"\int (x^2 - y)dx", Integral(x**2 - y, x)),
def test_Derivative():
assert str(Derivative(x, y)) == "Derivative(x, y)"
assert str(Derivative(x**2, x, evaluate=False)) == "Derivative(x**2, x)"
assert str(Derivative(
x**2/y, x, y, evaluate=False)) == "Derivative(x**2/y, x, y)"
def _eval_derivative(self, x):
if x.is_real or self.args[0].is_real:
return im(Derivative(self.args[0], x, **{'evaluate': True}))
if x.is_imaginary or self.args[0].is_imaginary:
return -S.ImaginaryUnit \
* re(Derivative(self.args[0], x, **{'evaluate': True}))
def test_issue_16160():
assert Derivative(x**3, (x, x)).subs(x, 2) == Subs(
Derivative(x**3, (x, 2)), x, 2)
assert Derivative(1 + x**3, (x, x)).subs(x, 0
) == Derivative(1 + y**3, (y, 0)).subs(y, 0)
def test_Derivative():
assert precedence(Derivative(x, y)) == PRECEDENCE["Atom"]
def _eval_derivative(self, t):
x, y = re(self.args[0]), im(self.args[0])
return (x * Derivative(y, t, **{'evaluate': True}) -
y * Derivative(x, t, **{'evaluate': True})) / (x**2 + y**2)
def test_del_operator():
#Tests for curl
assert (delop
^ Vector.zero == (Derivative(0, C.y) - Derivative(0, C.z)) * C.i +
(-Derivative(0, C.x) + Derivative(0, C.z)) * C.j +
(Derivative(0, C.x) - Derivative(0, C.y)) * C.k)
assert ((delop ^ Vector.zero).doit() == Vector.zero == curl(
Vector.zero, C))
assert delop.cross(Vector.zero) == delop ^ Vector.zero
assert (delop ^ i).doit() == Vector.zero
assert delop.cross(2 * y**2 * j, doit=True) == Vector.zero
assert delop.cross(2 * y**2 * j) == delop ^ 2 * y**2 * j
v = x * y * z * (i + j + k)
assert ((delop ^ v).doit() == (-x * y + x * z) * i + (x * y - y * z) * j +
(-x * z + y * z) * k == curl(v, C))
assert delop ^ v == delop.cross(v)
assert (delop.cross(
2 * x**2 *
j) == (Derivative(0, C.y) - Derivative(2 * C.x**2, C.z)) * C.i +
(-Derivative(0, C.x) + Derivative(0, C.z)) * C.j +
(-Derivative(0, C.y) + Derivative(2 * C.x**2, C.x)) * C.k)
assert (delop.cross(2 * x**2 * j, doit=True) == 4 * x * k == curl(
2 * x**2 * j, C))
#Tests for divergence
assert delop & Vector.zero == S(0) == divergence(Vector.zero, C)
assert (delop & Vector.zero).doit() == S(0)
assert delop.dot(Vector.zero) == delop & Vector.zero
assert (delop & i).doit() == S(0)
assert (delop & x**2 * i).doit() == 2 * x == divergence(x**2 * i, C)
assert (delop.dot(v, doit=True) == x * y + y * z + z * x == divergence(
v, C))
assert delop & v == delop.dot(v)
assert delop.dot(1/(x*y*z) * (i + j + k), doit = True) == \
- 1 / (x*y*z**2) - 1 / (x*y**2*z) - 1 / (x**2*y*z)
v = x * i + y * j + z * k
assert (delop & v == Derivative(C.x, C.x) + Derivative(C.y, C.y) +
Derivative(C.z, C.z))
assert delop.dot(v, doit=True) == 3 == divergence(v, C)
assert delop & v == delop.dot(v)
assert simplify((delop & v).doit()) == 3
#Tests for gradient
assert (delop.gradient(0, doit=True) == Vector.zero == gradient(0, C))
assert delop.gradient(0) == delop(0)
assert (delop(S(0))).doit() == Vector.zero
assert (delop(x) == (Derivative(C.x, C.x)) * C.i +
(Derivative(C.x, C.y)) * C.j + (Derivative(C.x, C.z)) * C.k)
assert (delop(x)).doit() == i == gradient(x, C)
assert (delop(x * y * z) == (Derivative(C.x * C.y * C.z, C.x)) * C.i +
(Derivative(C.x * C.y * C.z, C.y)) * C.j +
(Derivative(C.x * C.y * C.z, C.z)) * C.k)
assert (delop.gradient(x * y * z, doit=True) ==
y * z * i + z * x * j + x * y * k == gradient(x * y * z, C))
assert delop(x * y * z) == delop.gradient(x * y * z)
assert (delop(2 * x**2)).doit() == 4 * x * i
assert ((delop(a * sin(y) / x)).doit() == -a * sin(y) / x**2 * i +
a * cos(y) / x * j)
#Tests for directional derivative
assert (Vector.zero & delop)(a) == S(0)
assert ((Vector.zero & delop)(a)).doit() == S(0)
assert ((v & delop)(Vector.zero)).doit() == Vector.zero
assert ((v & delop)(S(0))).doit() == S(0)
assert ((i & delop)(x)).doit() == 1
assert ((j & delop)(y)).doit() == 1
assert ((k & delop)(z)).doit() == 1
assert ((i & delop)(x * y * z)).doit() == y * z
assert ((v & delop)(x)).doit() == x
assert ((v & delop)(x * y * z)).doit() == 3 * x * y * z
assert (v & delop)(x + y + z) == C.x + C.y + C.z
assert ((v & delop)(x + y + z)).doit() == x + y + z
assert ((v & delop)(v)).doit() == v
assert ((i & delop)(v)).doit() == i
assert ((j & delop)(v)).doit() == j
assert ((k & delop)(v)).doit() == k
assert ((v & delop)(Vector.zero)).doit() == Vector.zero
def _eval_derivative(self, symbol):
new_expr = Derivative(self.expr, symbol)
return DifferentialOperator(new_expr, self.args[-1])
def test_twave():
A1, phi1, A2, phi2, f = symbols('A1, phi1, A2, phi2, f')
n = Symbol('n') # Refractive index
t = Symbol('t') # Time
x = Symbol('x') # Spatial variable
E = Function('E')
w1 = TWave(A1, f, phi1)
w2 = TWave(A2, f, phi2)
assert w1.amplitude == A1
assert w1.frequency == f
assert w1.phase == phi1
assert w1.wavelength == c / (f * n)
assert w1.time_period == 1 / f
assert w1.angular_velocity == 2 * pi * f
assert w1.wavenumber == 2 * pi * f * n / c
assert w1.speed == c / n
w3 = w1 + w2
assert w3.amplitude == sqrt(A1**2 + 2 * A1 * A2 * cos(phi1 - phi2) + A2**2)
assert w3.frequency == f
assert w3.phase == atan2(A1 * sin(phi1) + A2 * sin(phi2),
A1 * cos(phi1) + A2 * cos(phi2))
assert w3.wavelength == c / (f * n)
assert w3.time_period == 1 / f
assert w3.angular_velocity == 2 * pi * f
assert w3.wavenumber == 2 * pi * f * n / c
assert w3.speed == c / n
assert simplify(w3.rewrite(sin) - w2.rewrite(sin) - w1.rewrite(sin)) == 0
assert w3.rewrite('pde') == epsilon * mu * Derivative(E(
x, t), t, t) + Derivative(E(x, t), x, x)
assert w3.rewrite(
cos) == sqrt(A1**2 + 2 * A1 * A2 * cos(phi1 - phi2) +
A2**2) * cos(pi * f * n * x * s /
(149896229 * m) - 2 * pi * f * t +
atan2(A1 * sin(phi1) + A2 * sin(phi2),
A1 * cos(phi1) + A2 * cos(phi2)))
assert w3.rewrite(
exp) == sqrt(A1**2 + 2 * A1 * A2 * cos(phi1 - phi2) + A2**2) * exp(
I * (-2 * pi * f * t + atan2(A1 * sin(phi1) + A2 * sin(phi2),
A1 * cos(phi1) + A2 * cos(phi2)) +
pi * s * f * n * x / (149896229 * m)))
w4 = TWave(A1, None, 0, 1 / f)
assert w4.frequency == f
w5 = w1 - w2
assert w5.amplitude == sqrt(A1**2 - 2 * A1 * A2 * cos(phi1 - phi2) + A2**2)
assert w5.frequency == f
assert w5.phase == atan2(A1 * sin(phi1) - A2 * sin(phi2),
A1 * cos(phi1) - A2 * cos(phi2))
assert w5.wavelength == c / (f * n)
assert w5.time_period == 1 / f
assert w5.angular_velocity == 2 * pi * f
assert w5.wavenumber == 2 * pi * f * n / c
assert w5.speed == c / n
assert simplify(w5.rewrite(sin) - w1.rewrite(sin) + w2.rewrite(sin)) == 0
assert w5.rewrite('pde') == epsilon * mu * Derivative(E(
x, t), t, t) + Derivative(E(x, t), x, x)
assert w5.rewrite(cos) == sqrt(
A1**2 - 2 * A1 * A2 * cos(phi1 - phi2) +
A2**2) * cos(-2 * pi * f * t + atan2(A1 * sin(phi1) - A2 * sin(phi2),
A1 * cos(phi1) - A2 * cos(phi2)) +
pi * s * f * n * x / (149896229 * m))
assert w5.rewrite(
exp) == sqrt(A1**2 - 2 * A1 * A2 * cos(phi1 - phi2) + A2**2) * exp(
I * (-2 * pi * f * t + atan2(A1 * sin(phi1) - A2 * sin(phi2),
A1 * cos(phi1) - A2 * cos(phi2)) +
pi * s * f * n * x / (149896229 * m)))
w6 = 2 * w1
assert w6.amplitude == 2 * A1
assert w6.frequency == f
assert w6.phase == phi1
w7 = -w6
assert w7.amplitude == -2 * A1
assert w7.frequency == f
assert w7.phase == phi1
raises(ValueError, lambda: TWave(A1))
raises(ValueError, lambda: TWave(A1, f, phi1, t))
def _eval_derivative(self, t):
x, y = self.args[0].as_real_imag()
return (x * Derivative(y, t, evaluate=True) - y *
Derivative(x, t, evaluate=True)) / (x**2 + y**2)
def curl(vect, coord_sys=None, doit=True):
"""
Returns the curl of a vector field computed wrt the base scalars
of the given coordinate system.
Parameters
==========
vect : Vector
The vector operand
coord_sys : CoordSys3D
The coordinate system to calculate the gradient in.
Deprecated since version 1.1
doit : bool
If True, the result is returned after calling .doit() on
each component. Else, the returned expression contains
Derivative instances
Examples
========
>>> from sympy.vector import CoordSys3D, curl
>>> R = CoordSys3D('R')
>>> v1 = R.y*R.z*R.i + R.x*R.z*R.j + R.x*R.y*R.k
>>> curl(v1)
0
>>> v2 = R.x*R.y*R.z*R.i
>>> curl(v2)
R.x*R.y*R.j + (-R.x*R.z)*R.k
"""
coord_sys = _get_coord_sys_from_expr(vect, coord_sys)
if len(coord_sys) == 0:
return Vector.zero
elif len(coord_sys) == 1:
coord_sys = next(iter(coord_sys))
i, j, k = coord_sys.base_vectors()
x, y, z = coord_sys.base_scalars()
h1, h2, h3 = coord_sys.lame_coefficients()
vectx = vect.dot(i)
vecty = vect.dot(j)
vectz = vect.dot(k)
outvec = Vector.zero
outvec += (Derivative(vectz * h3, y) -
Derivative(vecty * h2, z)) * i / (h2 * h3)
outvec += (Derivative(vectx * h1, z) -
Derivative(vectz * h3, x)) * j / (h1 * h3)
outvec += (Derivative(vecty * h2, x) -
Derivative(vectx * h1, y)) * k / (h2 * h1)
if doit:
return outvec.doit()
return outvec
else:
if isinstance(vect, (Add, VectorAdd)):
from sympy.vector import express
try:
cs = next(iter(coord_sys))
args = [express(i, cs, variables=True) for i in vect.args]
except ValueError:
args = vect.args
return VectorAdd.fromiter(curl(i, doit=doit) for i in args)
elif isinstance(vect, (Mul, VectorMul)):
vector = [
i for i in vect.args
if isinstance(i, (Vector, Cross, Gradient))
][0]
scalar = Mul.fromiter(
i for i in vect.args
if not isinstance(i, (Vector, Cross, Gradient)))
res = Cross(gradient(scalar),
vector).doit() + scalar * curl(vector, doit=doit)
if doit:
return res.doit()
return res
elif isinstance(vect, (Cross, Curl, Gradient)):
return Curl(vect)
else:
raise Curl(vect)
def test_Derivative_kind():
A = MatrixSymbol('A', 2, 2)
assert Derivative(comm_x, comm_x).kind is NumberKind
assert Derivative(A, comm_x).kind is MatrixKind(NumberKind)
def unreplace(eq, var):
return eq.replace(diffx, lambda e: Derivative(e, var))
def _eval_derivative(self, x):
if x.is_real:
return conjugate(Derivative(self.args[0], x, evaluate=True))
elif x.is_imaginary:
return -conjugate(Derivative(self.args[0], x, evaluate=True))
def test_big_expr():
f = Function('f')
x = symbols('x')
e1 = Dagger(AntiCommutator(Operator('A') + Operator('B'), Pow(DifferentialOperator(Derivative(f(x), x), f(x)), 3))*TensorProduct(Jz**2, Operator('A') + Operator('B')))*(JzBra(1, 0) + JzBra(1, 1))*(JzKet(0, 0) + JzKet(1, -1))
e2 = Commutator(Jz**2, Operator('A') + Operator('B'))*AntiCommutator(Dagger(Operator('C')*Operator('D')), Operator('E').inv()**2)*Dagger(Commutator(Jz, J2))
e3 = Wigner3j(1, 2, 3, 4, 5, 6)*TensorProduct(Commutator(Operator('A') + Dagger(Operator('B')), Operator('C') + Operator('D')), Jz - J2)*Dagger(OuterProduct(Dagger(JzBra(1, 1)), JzBra(1, 0)))*TensorProduct(JzKetCoupled(1, 1, (1, 1)) + JzKetCoupled(1, 0, (1, 1)), JzKetCoupled(1, -1, (1, 1)))
e4 = (ComplexSpace(1)*ComplexSpace(2) + FockSpace()**2)*(L2(Interval(
0, oo)) + HilbertSpace())
assert str(e1) == '(Jz**2)x(Dagger(A) + Dagger(B))*{Dagger(DifferentialOperator(Derivative(f(x), x),f(x)))**3,Dagger(A) + Dagger(B)}*(<1,0| + <1,1|)*(|0,0> + |1,-1>)'
ascii_str = \
"""\
/ 3 \\ \n\
|/ +\\ | \n\
2 / + +\\ <| /d \\ | + +> \n\
/J \\ x \\A + B /*||DifferentialOperator|--(f(x)),f(x)| | ,A + B |*(<1,0| + <1,1|)*(|0,0> + |1,-1>)\n\
\\ z/ \\\\ \\dx / / / \
"""
ucode_str = \
"""\
⎧ 3 ⎫ \n\
⎪⎛ †⎞ ⎪ \n\
2 ⎛ † †⎞ ⎨⎜ ⎛d ⎞ ⎟ † †⎬ \n\
⎛J ⎞ ⨂ ⎝A + B ⎠⋅⎪⎜DifferentialOperator⎜──(f(x)),f(x)⎟ ⎟ ,A + B ⎪⋅(⟨1,0❘ + ⟨1,1❘)⋅(❘0,0⟩ + ❘1,-1⟩)\n\
⎝ z⎠ ⎩⎝ ⎝dx ⎠ ⎠ ⎭ \
"""
assert pretty(e1) == ascii_str
assert upretty(e1) == ucode_str
assert latex(e1) == \
r'{J_z^{2}}\otimes \left({A^{\dagger} + B^{\dagger}}\right) \left\{\left(DifferentialOperator\left(\frac{d}{d x} f{\left(x \right)},f{\left(x \right)}\right)^{\dagger}\right)^{3},A^{\dagger} + B^{\dagger}\right\} \left({\left\langle 1,0\right|} + {\left\langle 1,1\right|}\right) \left({\left|0,0\right\rangle } + {\left|1,-1\right\rangle }\right)'
sT(e1, "Mul(TensorProduct(Pow(JzOp(Symbol('J')), Integer(2)), Add(Dagger(Operator(Symbol('A'))), Dagger(Operator(Symbol('B'))))), AntiCommutator(Pow(Dagger(DifferentialOperator(Derivative(Function('f')(Symbol('x')), Tuple(Symbol('x'), Integer(1))),Function('f')(Symbol('x')))), Integer(3)),Add(Dagger(Operator(Symbol('A'))), Dagger(Operator(Symbol('B'))))), Add(JzBra(Integer(1),Integer(0)), JzBra(Integer(1),Integer(1))), Add(JzKet(Integer(0),Integer(0)), JzKet(Integer(1),Integer(-1))))")
assert str(e2) == '[Jz**2,A + B]*{E**(-2),Dagger(D)*Dagger(C)}*[J2,Jz]'
ascii_str = \
"""\
[ 2 ] / -2 + +\\ [ 2 ]\n\
[/J \\ ,A + B]*<E ,D *C >*[J ,J ]\n\
[\\ z/ ] \\ / [ z]\
"""
ucode_str = \
"""\
⎡ 2 ⎤ ⎧ -2 † †⎫ ⎡ 2 ⎤\n\
⎢⎛J ⎞ ,A + B⎥⋅⎨E ,D ⋅C ⎬⋅⎢J ,J ⎥\n\
⎣⎝ z⎠ ⎦ ⎩ ⎭ ⎣ z⎦\
"""
assert pretty(e2) == ascii_str
assert upretty(e2) == ucode_str
assert latex(e2) == \
r'\left[J_z^{2},A + B\right] \left\{E^{-2},D^{\dagger} C^{\dagger}\right\} \left[J^2,J_z\right]'
sT(e2, "Mul(Commutator(Pow(JzOp(Symbol('J')), Integer(2)),Add(Operator(Symbol('A')), Operator(Symbol('B')))), AntiCommutator(Pow(Operator(Symbol('E')), Integer(-2)),Mul(Dagger(Operator(Symbol('D'))), Dagger(Operator(Symbol('C'))))), Commutator(J2Op(Symbol('J')),JzOp(Symbol('J'))))")
assert str(e3) == \
"Wigner3j(1, 2, 3, 4, 5, 6)*[Dagger(B) + A,C + D]x(-J2 + Jz)*|1,0><1,1|*(|1,0,j1=1,j2=1> + |1,1,j1=1,j2=1>)x|1,-1,j1=1,j2=1>"
ascii_str = \
"""\
[ + ] / 2 \\ \n\
/1 3 5\\*[B + A,C + D]x |- J + J |*|1,0><1,1|*(|1,0,j1=1,j2=1> + |1,1,j1=1,j2=1>)x |1,-1,j1=1,j2=1>\n\
| | \\ z/ \n\
\\2 4 6/ \
"""
ucode_str = \
"""\
⎡ † ⎤ ⎛ 2 ⎞ \n\
⎛1 3 5⎞⋅⎣B + A,C + D⎦⨂ ⎜- J + J ⎟⋅❘1,0⟩⟨1,1❘⋅(❘1,0,j₁=1,j₂=1⟩ + ❘1,1,j₁=1,j₂=1⟩)⨂ ❘1,-1,j₁=1,j₂=1⟩\n\
⎜ ⎟ ⎝ z⎠ \n\
⎝2 4 6⎠ \
"""
assert pretty(e3) == ascii_str
assert upretty(e3) == ucode_str
assert latex(e3) == \
r'\left(\begin{array}{ccc} 1 & 3 & 5 \\ 2 & 4 & 6 \end{array}\right) {\left[B^{\dagger} + A,C + D\right]}\otimes \left({- J^2 + J_z}\right) {\left|1,0\right\rangle }{\left\langle 1,1\right|} \left({{\left|1,0,j_{1}=1,j_{2}=1\right\rangle } + {\left|1,1,j_{1}=1,j_{2}=1\right\rangle }}\right)\otimes {{\left|1,-1,j_{1}=1,j_{2}=1\right\rangle }}'
sT(e3, "Mul(Wigner3j(Integer(1), Integer(2), Integer(3), Integer(4), Integer(5), Integer(6)), TensorProduct(Commutator(Add(Dagger(Operator(Symbol('B'))), Operator(Symbol('A'))),Add(Operator(Symbol('C')), Operator(Symbol('D')))), Add(Mul(Integer(-1), J2Op(Symbol('J'))), JzOp(Symbol('J')))), OuterProduct(JzKet(Integer(1),Integer(0)),JzBra(Integer(1),Integer(1))), TensorProduct(Add(JzKetCoupled(Integer(1),Integer(0),Tuple(Integer(1), Integer(1)),Tuple(Tuple(Integer(1), Integer(2), Integer(1)))), JzKetCoupled(Integer(1),Integer(1),Tuple(Integer(1), Integer(1)),Tuple(Tuple(Integer(1), Integer(2), Integer(1))))), JzKetCoupled(Integer(1),Integer(-1),Tuple(Integer(1), Integer(1)),Tuple(Tuple(Integer(1), Integer(2), Integer(1))))))")
assert str(e4) == '(C(1)*C(2)+F**2)*(L2(Interval(0, oo))+H)'
ascii_str = \
"""\
// 1 2\\ x2\\ / 2 \\\n\
\\\\C x C / + F / x \\L + H/\
"""
ucode_str = \
"""\
⎛⎛ 1 2⎞ ⨂2⎞ ⎛ 2 ⎞\n\
⎝⎝C ⨂ C ⎠ ⊕ F ⎠ ⨂ ⎝L ⊕ H⎠\
"""
assert pretty(e4) == ascii_str
assert upretty(e4) == ucode_str
assert latex(e4) == \
r'\left(\left(\mathcal{C}^{1}\otimes \mathcal{C}^{2}\right)\oplus {\mathcal{F}}^{\otimes 2}\right)\otimes \left({\mathcal{L}^2}\left( \left[0, \infty\right) \right)\oplus \mathcal{H}\right)'
sT(e4, "TensorProductHilbertSpace((DirectSumHilbertSpace(TensorProductHilbertSpace(ComplexSpace(Integer(1)),ComplexSpace(Integer(2))),TensorPowerHilbertSpace(FockSpace(),Integer(2)))),(DirectSumHilbertSpace(L2(Interval(Integer(0), oo, false, true)),HilbertSpace())))")
def test_derivative2():
f = Function("f")
x = Symbol("x")
a = Wild("a", exclude=[f, x])
b = Wild("b", exclude=[f])
e = Derivative(f(x), x)
assert e.match(Derivative(f(x), x)) == {}
assert e.match(Derivative(f(x), x, x)) is None
e = Derivative(f(x), x, x)
assert e.match(Derivative(f(x), x)) is None
assert e.match(Derivative(f(x), x, x)) == {}
e = Derivative(f(x), x) + x**2
assert e.match(a*Derivative(f(x), x) + b) == {a: 1, b: x**2}
assert e.match(a*Derivative(f(x), x, x) + b) is None
e = Derivative(f(x), x, x) + x**2
assert e.match(a*Derivative(f(x), x) + b) is None
assert e.match(a*Derivative(f(x), x, x) + b) == {a: 1, b: x**2}
def _eval_derivative(self, x):
if self.args[0].is_real:
return Derivative(self.args[0], x, **{'evaluate': True}) * sign(self.args[0])
return (re(self.args[0]) * re(Derivative(self.args[0], x,
**{'evaluate': True})) + im(self.args[0]) * im(Derivative(self.args[0],
x, **{'evaluate': True}))) / Abs(self.args[0])
