Python 数组只有 1D，我不能使用 reshape 将其转换为 2D

Question

我创建了两个程序来对化学反应系统进行随机模拟。在程序中，我有一个函数，该函数旨在使用不断变化的分子数popul_num 的derivative 和每个反应的随机速率常数stoch_rate 更新数组的元素@ 在第一个程序中，函数看起来像如下：

popul_num = np.array([1.0E9, 0, 0])
stoch_rate = np.array([1.0, 0.002, 0.5, 0.04])

def update_array(popul_num, stoch_rate): 
    """Specific to this model 
    will need to change if different model 
    implements equaiton 24 of the Gillespie paper""" 
    # calcualte in seperate varaible then pass it into the array 
    s_derviative = stoch_rate[1]*(2*popul_num[0] -1)/2
    b = np.array([[1.0, 0.0, 0.0], [s_derviative, 0.0, 0.0], [0.0, 0.5, 0.0], [0.0, 0.4, 0.0]])
    return b 

此函数返回b，它是shape(4, 3) 的array

在下一个程序中，我添加了更多的反应和更多的反应物，功能如下：

popul_num = np.array([1.0E5, 3.0E5, 0.0, 1.0E5, 0.0, 0.0, 0.0, 0.0])
stoch_rate = np.array([0.015, 0.00016, 0.5, 0.002, 0.002, 0.8])

def update_array(popul_num, stoch_rate): 
    """Specific to this model 
    will need to change if different model 
    implements equaiton 24 of the Gillespie paper"""
    s_derivative = stoch_rate[0]*popul_num[1]*((popul_num[1] - 1)/2)   # derivative with respect to S is a function of X
    x_derivative = stoch_rate[0]*popul_num[0]*((2*popul_num[1] - 1)/2) # derivative with respect to X is a function of S
    r_derivative = stoch_rate[1]*((popul_num[3]*(popul_num[3]))/2)  
    r2_derivative = stoch_rate[2]*popul_num[4] # derivative with respect to R is a function of Y type = numpy.float64
    y_derivative = stoch_rate[3]*popul_num[3] # derivative with respect to Y is a function of R type = numpy.float64
    x2_derivative = stoch_rate[4]*((popul_num[1] - 1)/2)
    b = np.array([[x_derivative, s_derivative, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 
r_derivative, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, r2_derivative, y_derivative, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, stoch_rate[3], 0.0, 0.0, 0.0, 0.0], [x2_derivative, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, stoch_rate[5], 0.0]]) 
    b.reshape((6,8))
    print("Shape b:\n", b.shape)
    return b

只有这会返回shape(6,) 的array，我需要它是shape(6, 8) 的二维数组我尝试使用reshape() 方法，但这会导致以下错误：

ValueError: cannot reshape array of size 6 into shape (6,8)

在我调用reshape() 命令的那一行被抛出

我不明白第二个函数有什么不同意味着它不返回二维数组？

干杯

Answer 1

缺少一个值。此列表仅包含 7 个值：

 [x2_derivative, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]