Question

我已经编写了一个解决方程组的函数，但是当我的解决方案中有一个平方根时，它确实不起作用。只要没有平方根，代码就可以用于其他方程。

我收到以下错误

TypeError: No loop matching the specified signature and casting
was found for ufunc solve1

我可以计算sqrt并得到一个十进制数，但我不想要那个。我需要用完整的数字进行计算，我宁愿让它返回sqrt（5）而不是2.236067977

我目前正在尝试解决以下重现关系

eqs :=
[
s(n) = s(n-1)+s(n-2),
s(0) = 1,
s(1) = 1
];

我已经记下了我的输出并且在这里顺着步骤。它适用于没有平方根的方程。如何让linalg与sqrt一起使用，还是应该使用不同的方法？

def solve_homogeneous_equation(init_conditions, associated):
    # Write down characteristic equation for r
    Returns eq_string = r^2-1*r^(2-1)-+1*r^(2-2)

    # Find the roots for r
    Returns r_solutions = [1/2 + sqrt(5)/2, -sqrt(5)/2 + 1/2]

    # Write down general solution (for solver)
    Returns two lists, one with variables and one with outcomes
    general_solution_variables = [[1, 1], [1/2 + sqrt(5)/2, -sqrt(5)/2 + 1/2]]
    general_solution_outcomes = [1, 1]

    # Solve the system of equations
    THIS IS WHERE THE ERROR OCCURS
    solution = np.linalg.solve(general_solution_variables, general_solution_outcomes)

    # Write the solution
    This is where I rewrite the general solution with found solutions

原始函数在此定义，以防您想深入了解代码

def solve_homogeneous_equation(init_conditions, associated):
    print("Starting solver")
    # Write down characteristic equation for r
    eq_length = len(init_conditions)
    associated[0] = str('r^' + str(eq_length))
    for i in range(eq_length, 0, -1):
        if i in associated.keys() :
            associated[i] = associated[i] + str('*r^(') + str(eq_length) + str('-') + str(i) + str(')')
    print("Associated equation: " + str(associated))
    eq_string = ''
    for i in range(0, eq_length+1, 1):
        if i in associated.keys():
            if i < eq_length:
                eq_string = eq_string + associated[i] + '-'
            else:
                eq_string = eq_string + associated[i]
    print("Equation: " + eq_string)

    # Find the roots for r
    r_symbol = sy.Symbol('r')
    r_solutions = sy.solve(eq_string, r_symbol)
    r_length = len(r_solutions)
    print("Solutions: " + str(r_solutions))
    print("Eq length: " + str(eq_length) + " ; Amount of solutions: " + str(r_length))

    # If equation length is equal to solutions
    if eq_length == r_length:

        # Write down general solution (for solver)
        general_solution_variables = []
        general_solution_outcomes = []
        for i in range(0, eq_length):
            general_solution_variables_single = []
            for j in range(0, eq_length + 1):
                if j != eq_length:
                    k = r_solutions[j]**i
                    general_solution_variables_single.append(k)
                if j == eq_length:
                    k = init_conditions[i]
                    general_solution_outcomes.append(int(k))
            general_solution_variables.append(general_solution_variables_single)
        print("General solution variables: " + str(general_solution_variables))
        print("General solution outcomes: " + str(general_solution_outcomes))

        # Solve the system of equations
        solution = np.linalg.solve(general_solution_variables, general_solution_outcomes)
        print("Solutions: " + str(solution))

        # Write the solution
        solution_full = ""
        for i in range(0, eq_length):
            if i > 0:
                solution_full = solution_full + " + "
            solution_full = solution_full + str(int(solution[i])) + "*" + str(int(r_solutions[i])) + "^n"
        print("Solved equation: " + solution_full)
        return(solution_full)

    # If equation length is not equal to solutions
    elif eq_length > r_length:
        print("NonEqual")
        return 0

Answer 1

我没有努力阅读你的代码。我注意到您可以使用sympy以符号方式解决该系统。

与通常一样，函数定义和方程中的同义词必须全部移到等号的一边。
初始条件以字典传递。

public class Coursenode {

    private Course data;
    private Coursenode next;

    public Coursenode() {
        this.data = null;
        this.next = null;
    }

    public Coursenode(Course course, Coursenode next) {
        this.data=course;
        this.next= next;
    }

    public Coursenode(Coursenode x) {
        this.data = x.getData();
        this.next = x.getNext();
    }

    public Course getData() {
        return data;
    }

    public void setData(Course data) {
        this.data = data;
    }

    public Coursenode getNext() {
        return next;
    }

    public void setNext(Coursenode next) {
        this.next = next;
    }

    //Clone method
    public void clone(Coursenode new_cn){ 
         new_cn = new Coursenode (this.getData(),this.getNext());
    }
}

Python求平方根方程组

1 个答案: