我正在尝试定义阿基米德螺旋线:当我尝试定义切线向量与轨道的倾角(包括)时(即:tan(incl))
我收到一个错误:
'numpy.ufunc' 对象不支持项目分配”和“不能分配给函数调用”
当我想计算cos(incl)
和时,同样的错误sin(incl)
。任何建议和帮助。
我的代码是:
T = 100
N = 10000
dt = float(T)/N
D = 2
DII = 10
a = 2.
v = 0.23
omega = 0.2
r0 = v/omega
t = np.linspace(0,T,N+1)
r = v*t
theta = a + r/r0
theta = omega*t
x = r * np.cos(omega*t)
y = r * np.sin(omega*t)
dxdr = np.cos(theta) - (r/r0)*np.sin(theta)
dydr = np.sin(theta) + (r/r0)*np.cos(theta)
dydx = (r0*np.sin(theta) + r*np.cos(theta))/r0*np.cos(theta) - r*np.sin(theta)
np.tan[incl] = dydx
incl = np.arctan((dydx))
### Calculate cos(incl) ,sin(incl) :
np.sin[np.incl] = np.tan(np.incl)/np.sqrt(1 + np.tan(np.incl)*2)
np.cos[incl] = 1/np.sqrt(1 + np.tan(incl)*2)
p1, = plt.plot(xx, yy)
i= 0 # this is the first value of the array
Bx = np.array([np.cos(i), -np.sin(i)])
By = np.array([np.sin(i), np.cos(i)])
n = 1000
seed(2)
finalpositions = []
for number in range(0, 10):
x = []
y = []
x.append(0)
y.append(0)
for i in range(n):
s = np.random.normal(0, 1, 2)
deltaX = Bx[0]*np.sqrt(2*DII*dt)*s[0] + Bx[1]*np.sqrt(2*D*dt)*s[1]
deltaY = By[0]*np.sqrt(2*DII*dt)*s[0] + By[1]*np.sqrt(2*D*dt)*s[1]
x.append(x[-1] + deltaX)
y.append(y[-1] + deltaY)
finalpositions.append([x[-1], y[-1]])
p2, = plt.plot(finalpositions[:,0],finalpositions[:,1],'*')
plt.show()