我尝试使用cupy而不是numpy来加快我的Python代码速度。然而问题在于,使用cupy后,我的代码速度变得更慢了。也许我在这个问题上有点太天真了。
也许有人能够找到我的代码中的瓶颈:
import cupy as np
import time as ti
def f(y, t):
y_ = np.zeros(2 * N_1*N_2) # n: e-6, c: e-5
for i in range(0, N_1*N_2):
y_[i] = y[i + N_1*N_2] # n: e-7, c: e-5 or e-6
for i in range(N_1*N_2):
sum = -4*y[i] # n: e-7, c: e-7 after some statements e-5
if (i + 1 in indexes) and (not (i in indi)):
sum += y[i+1] # n: e-7, c: e-7 after some statements e-5
if (i - 1) in indexes and (i % N_1 != 0):
sum += y[i-1] # n: e-7, c: e-7 after some statements e-5
if i + N_1 in indexes:
sum += y[i+N_1] # n: e-7, c: e-7 after some statements e-5
if i - N_1 in indexes:
sum += y[i-N_1] # n: e-7, c: e-7 after some statements e-5
y_[i + N_1*N_2] = sum
return y_
def k_1(y, t, h):
return np.asarray(f(y, t)) * h
def k_2(y, t, h):
return np.asarray(f(np.add(np.asarray(y) , np.multiply(1/2 , k_1(y, t, h))), t + 1/2 * h)) * h
# k_2, k_4 look just like k_2, may be with an 1/2 here or there
# some init stuff is happening here
while t < T_end:
# also some magic happening here which is just data saving
y = np.asarray(y) + 1/6*(k_1(y, t, m) + 2*k_2(y, t, m) + 2*k_3(y, t, m) + k_4(y, t, m))
t += m
编辑 我试图对我的代码进行基准测试,以下是一些结果,它们可以作为代码中的注释查看。每个数字代表一行。单位是秒。n:Numpy,c:CuPy,我主要给出了大致顺序的估计值。 此外,我还进行了其他测试。
np.multiply # n: e-6, c: e-5
and
np.add # n: e-5 or e-6, c: 0.005 or e-5