Python 用辛方法解一组4符号方程时的属性错误
我想解一个由4个方程组成的系统,如下所示:Python 用辛方法解一组4符号方程时的属性错误,python,sympy,symbols,equation,symbolic-math,Python,Sympy,Symbols,Equation,Symbolic Math,我想解一个由4个方程组成的系统,如下所示: x1 = b1*a1 + b2*a2 + b3*a3 + b4*a4 x2 = b1*a5 + b2*a6 + b3*a7 + b4*a8 x3 = b1*a9 + b2*a10 + b3*a11 + b4*a12 x4 = b1*a13 + b2*a14 + b3*a15 + b4*a16 其中,我的目标是找到一个解决方案,使b1、b2、b3、b4由其他参数/符号定义 我的尝试是: import sympy as sy sy.init
x1 = b1*a1 + b2*a2 + b3*a3 + b4*a4
x2 = b1*a5 + b2*a6 + b3*a7 + b4*a8
x3 = b1*a9 + b2*a10 + b3*a11 + b4*a12
x4 = b1*a13 + b2*a14 + b3*a15 + b4*a16
其中,我的目标是找到一个解决方案,使b1、b2、b3、b4由其他参数/符号定义
我的尝试是:
import sympy as sy
sy.init_printing()
x1, x2, x3, x4, b1, b2, b3, b4, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14,
a15, a16 = sy.symbols('x1, x2, x3, x4, b1, b2, b3, b4, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
a11, a12, a13, a14, a15, a16')
print(sy.solve(((x1-b1*a1-b2*a2-b3*a3-b4*a4, x2-b1*a5-b2*a6-b3*a7-b4*a8,
x3-b1*a9-b2*a10-b3*a11-b4*a12,x4-b1*a13-b2*a14-b3*a15-b4*a16), [b1,b2,b3,b4])))
问题是我得到了以下错误:
print(sy.solve(((x1-b1*a1-b2*a2-b3*a3-b4*a4, x2-b1*a5-b2*a6-b3*a7-b4*a8, x3-b1*a9-b2*a10-b3*a11-b4*a12,x4-b1*a13-b2*a14-b3*a15-b4*a16), [b1,b2,b3,b4])))
File "C:\Users\Admin\AppData\Local\Programs\Python\Python39\lib\site-packages\sympy\solvers\solvers.py", line 858, in solve
symbols = set().union(*[fi.free_symbols for fi in f])
File "C:\Users\Admin\AppData\Local\Programs\Python\Python39\lib\site-packages\sympy\solvers\solvers.py", line 858, in <listcomp>
symbols = set().union(*[fi.free_symbols for fi in f])
AttributeError: 'list' object has no attribute 'free_symbols'
print(sy.solve((x1-b1*a1-b2*a2-b3*a3-b4*a4,x2-b1*a5-b2*a6-b3*a7-b4*a8,x3-b1*a9-b2*a10-b3*a11-b4*a12,x4-b1*a13-b2*a14-b3*a15-b4*a16),[b1,b2,b3,b3,b3,b4]))
文件“C:\Users\Admin\AppData\Local\Programs\Python\39\lib\site packages\sympy\solvers\solvers.py”,第858行,在solve中
symbols=set().union(*[fi.free\u f中fi的符号])
文件“C:\Users\Admin\AppData\Local\Programs\Python\39\lib\site packages\sympy\solvers\solvers.py”,第858行,在
symbols=set().union(*[fi.free\u f中fi的符号])
AttributeError:“list”对象没有“free\u symbols”属性
如何修复代码?您在不应该存在的方程式周围添加了额外的括号。下面是一个简单的例子:
将sympy作为sym导入
x、 y=符号('x,y')
打印(符号解算((x+y,x-y-1),[x,y]))
解决方法是移除这些支架:
print(sym.solve((x+y,x-y-1),[x,y]))
这样您就可以将两个参数传递给solve
。一个是方程组,另一个是符号列表。以前,您将一个参数作为元组传递
修复该问题并整理代码将提供:
import sympy as sym
sym.init_printing()
(
x1, x2, x3, x4,
b1, b2, b3, b4,
a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16,
) = sym.symbols('x1:5 b1:5 a1:17')
equations = [
x1 - b1*a1 - b2*a2 - b3*a3 - b4*a4,
x2 - b1*a5 - b2*a6 - b3*a7 - b4*a8,
x3 - b1*a9 - b2*a10 - b3*a11 - b4*a12,
x4 - b1*a13 - b2*a14 - b3*a15 - b4*a16,
]
unknowns = [b1, b2, b3, b4]
solution = sym.solve(equations, unknowns)
print(solution)
请注意,您也可以像Eq(x1,b1*a1+…)
一样使用Eq
,对于线性系统,最好使用linsolve
而不是solve