小编Chi*_*Rai的帖子

这是我在ubuntu 14.04上编译的程序

f95 First.f -o First

而且程序是

!My first program
program first
print *,'This is my first program'
end program first

我收到以下错误

Error:Non-numeric character at statement label at (1)
First.f:2.1:

program first

你如何解决这个错误？

我正在尝试将图例添加到曲面图但无法这样做.这是代码.

import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import random

def fun(x, y):
  return 0.063*x**2 + 0.0628*x*y - 0.15015876*x + 96.1659*y**2 - 74.05284306*y  +      14.319143466051


fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
x = y = np.arange(-1.0, 1.0, 0.05)
X, Y = np.meshgrid(x, y)
zs = np.array([fun(x,y) for x,y in zip(np.ravel(X), np.ravel(Y))])
Z = zs.reshape(X.shape)

ax.plot_surface(X, Y, Z)

ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Z')
plt.plot(color='red',label='Lyapunov function on XY plane',linewidth=4)  # Adding legend

plt.show()

请帮助.提前致谢.

我正在尝试为以下程序分离输出的实部和虚部。

import sympy as sp
a = sp.symbols('a', imaginary=True)
b=sp.symbols('b',real=True)
V=sp.symbols('V',imaginary=True)
a=4*sp.I
b=5
V=a+b
print V

请帮忙。提前致谢。

我正在尝试指定微分方程的边界条件。

# *y"= 900(y - 1 + 2x) ; y(0)=5, y(2)=10*

from sympy import *
x=symbols('x')
y, g = symbols('y g', cls=Function)
diffeq = (Eq(y(x).diff(x, x) - 900*y(x) + 900, 1800*x),y(0):5,y(2)=10)
A=dsolve(diffeq, y(x))
print A

但它显示错误

diffeq = (Eq(y(x).diff(x, x) - 900*y(x) + 900, 1800*x),y(0):5,y(2)=10)
                                                           ^
SyntaxError: invalid syntax

请帮忙。

以下代码根据x,y,z生成3x3矩阵.我想生成矩阵的行列式.但无法这样做.

import numpy as np
import sympy as sp
from sympy import *
from sympy.matrices import Matrix
x,y,z =sp.symbols('x,y,z')
H1=np.array([[x,y,z]])
H2=np.array([[0.0630,0.0314,-0.0001],[0.0314,96.1659,-0.0001],[-0.0001,-0.0001,0.0001]])
H3=H1.T
H=H1*H2*H3
print H

要查找上述矩阵的行列式,我使用以下命令.

H.det()

但它显示错误

AttributeError: 'numpy.ndarray' object has no attribute 'det' 

我试图在(x,y)=(0,0)处评估雅可比行列式,但无法这样做.

import sympy as sp
from sympy import *
import numpy as np
x,y=sp.symbols('x,y', real=True)
J = Function('J')(x,y)
f1=-y
f2=x - 3*y*(1-x**2)
f1x=diff(f1,x)
f1y=diff(f1,y)
f2x=diff(f2,x)
f2y=diff(f2,y)
J=np.array([[f1x,f1y],[f2x,f2y]])
J1=J(0,0)
print J1

对应的错误

---> 16 J1=J(0,0)

是

TypeError: 'numpy.ndarray' object is not callable