合集-第八章

8.4
摘要：-- coding: utf-8 -- """ Created on Tue Nov 12 13:41:18 2024 @author: 朱尧 """ import numpy as np import pandas as pd import sympy as sp sp.init_printing 阅读全文
posted @ 2024-11-12 14:07 世梦 阅读(11) 评论(0) 推荐(0)
8.5
摘要：-- coding: utf-8 -- """ Created on Tue Nov 12 14:07:58 2024 @author: 朱尧 """ import numpy as np import pandas as pd import sympy as sp sp.init_printing 阅读全文
posted @ 2024-11-12 14:08 世梦 阅读(5) 评论(0) 推荐(0)
ex8.3
摘要：import sympy as sp sp.var('x'); y=sp.Function('y') eq=y(x).diff(x)+2y(x)-2x**2-2*x s=sp.dsolve(eq, ics={y(0):1}) s=sp.simplify(s); print(s) 阅读全文
posted @ 2025-01-03 19:18 世梦 阅读(2) 评论(0) 推荐(0)
ex8.4
摘要：import sympy as sp sp.var('x'); y=sp.Function('y') eq=y(x).diff(x,2)-2*y(x).diff(x)+y(x)-sp.exp(x) con={y(0): 1, y(x).diff(x).subs(x,0): -1} s=sp.dsol 阅读全文
posted @ 2025-01-03 19:18 世梦 阅读(1) 评论(0) 推荐(0)
ex8.5
摘要：import sympy as sp sp.var('t'); y=sp.Function('y') u=sp.exp(-t)sp.cos(t) eq=y(t).diff(t,4)+10y(t).diff(t,3)+35y(t).diff(t,2)+ 50y(t).diff(t)+24*y(t)-u 阅读全文
posted @ 2025-01-03 19:19 世梦 阅读(3) 评论(0) 推荐(0)
ex8.6
摘要：import sympy as sp sp.var('t') sp.var('x1:4', cls=sp.Function) #定义3个符号函数 x = sp.Matrix([x1(t), x2(t), x3(t)]) #列向量 A = sp.Matrix([[3,-1,1],[2,0,-1],[1 阅读全文
posted @ 2025-01-03 19:19 世梦 阅读(1) 评论(0) 推荐(0)
ex8.7
摘要：from scipy.integrate import odeint import numpy as np import pylab as plt import sympy as sp dy = lambda y, x: -2y+2x2+2x #自变量在后面 xx = np.linspace(0,3 阅读全文
posted @ 2025-01-03 19:20 世梦 阅读(9) 评论(0) 推荐(0)
ex8.8
摘要：hfrom scipy.integrate import odeint import numpy as np import pylab as plt yx = lambda y,x: [y[1], np.sqrt(1+y[1]**2)/5/(1-x)] x0 = np.arange(0, 1, 0. 阅读全文
posted @ 2025-01-03 19:20 世梦 阅读(3) 评论(0) 推荐(0)