为此有解决方法吗? 尝试解决时,将Sympy 1.13.3与Python 3.13.1一起使用
y'(x)=y(x)^(1/3)
带有icy(0)=1
它给予
here是完整的代码notimplementedError:初始条件产生了太多的解决方案 对于常数
Sympy真的无法解决这个问题,还是我需要一些选项或设置才能使用?我是使用Sympy解决Ode的新手。这种颂歌只是正交颂,所以我期望在Sympy中解决它没有问题。
python Python 3.13.1(Main,Dec 4 2024,18:05:56)[GCC 14.2.1 20240910]在Linux上
from sympy import *
x=symbols('x')
y=Function('y')
dsolve(Eq(-y(x)**(1/3) + Derivative(y(x), x),0) , y(x), ics={y(0):1})
给了
> Traceback (most recent call last): File "<python-input-4>", line 1,
> in <module>
> dsolve(Eq(-y(x)**(1/3) + Derivative(y(x), x),0) , y(x), ics={y(0):1})
> ~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> File "/usr/lib/python3.13/site-packages/sympy/solvers/ode/ode.py",
> line 640, in dsolve
> return _helper_simplify(eq, hint, hints, simplify, ics=ics) File "/usr/lib/python3.13/site-packages/sympy/solvers/ode/ode.py", line
> 709, in _helper_simplify
> solved_constants = solve_ics([s], [r['func']], cons(s), ics) File "/usr/lib/python3.13/site-packages/sympy/solvers/ode/ode.py",
> line 817, in solve_ics
> raise NotImplementedError("Initial conditions produced too many solutions for constants") NotImplementedError: Initial conditions
> produced too many solutions for constants
> >>>
解决方案应为
ode:=diff(y(x),x)=y(x)^(1/3);
dsolve([ode,y(0)=1])
# y(x) = (9 + 6*x)^(3/2)/27
sympy可以在没有
ics
或其他提示的情况下解决这个问题 - 这是您所期望的吗?
>>> from sympy import *
>>> x = symbols("x")
>>> y = Function("y")
>>> exprs = dsolve(-y(x)**(1/3) + Derivative(y(x), x))
>>> exprs
[Eq(y(x), -2*sqrt(6)*(C1 + x)**(3/2)/9), Eq(y(x), 2*sqrt(6)*(C1 + x)**(3/2)/9)]
>>> for e in exprs:
... print(solve(Eq(e.rhs, 1), x)) # hack together y(0)=1
...
[-C1 - 3/4 - 3*sqrt(3)*I/4, -C1 - 3/4 + 3*sqrt(3)*I/4]
[3/2 - C1]