1

我正在尝试将 scikit-cuda 的包装器用于 cuSOLVER 函数，特别是我想执行 cusolverDnSgesvd 来计算实数矩阵上的全矩阵单精度 SVD。

使用此处和此处的代码作为参考，我设法做到了这一点：

import pycuda.autoinit
import pycuda.driver as drv
import pycuda.gpuarray as gpuarray
import numpy as np

from skcuda import cusolver


handle = cusolver.cusolverDnCreate()

m = 50
n = 25

a = np.asarray(np.random.random((m, n)))
a_gpu = gpuarray.to_gpu(a)

ldu = m
ldvt = n

s_gpu = gpuarray.empty(min(m, n), np.float32)
u_gpu = gpuarray.empty((ldu, m), np.float32)
vh_gpu = gpuarray.empty((n, n), np.float32)

work_size = cusolver.cusolverDnSgesvd_bufferSize(handle, m, n)

work = gpuarray.empty((m,n), np.float32)

u_gpu, s_gpu, vh_gpu = cusolver.cusolverDnSgesvd(
    handle=handle,
    jobu='A',
    jobvt='A',
    m=m,
    n=n,
    A=a,
    lda=m,
    S=s_gpu,
    U=u_gpu,
    ldu=ldu,
    VT=vh_gpu,
    ldvt=ldvt,
    Work=work,
    Lwork=work_size,
    rwork=None,
    devInfo=0
)

但是代码不起作用，可能是因为我弄乱了类型。

Traceback (most recent call last):
  File "/home/vektor/PycharmProjects/yancut/test_svd.py", line 44, in <module>
    devInfo=0
  File "/home/vektor/anaconda3/lib/python3.4/site-packages/skcuda/cusolver.py", line 577, in cusolverDnSgesvd
    int(A), lda, int(S), int(U),
TypeError: only length-1 arrays can be converted to Python scalars

我应该如何提供所有参数以便以正确的方式执行 SVD？

UPDATE1： 使用这个问题作为参考后，我编辑了我的代码，我得到了一个新的错误。

import pycuda.autoinit
import pycuda.driver as drv
import pycuda.gpuarray as gpuarray
import numpy as np

import ctypes

from skcuda import cusolver

rows = 20
cols = 10

a = np.asarray(np.random.random((rows, cols)))
a_gpu = gpuarray.to_gpu(a.copy())
lda = rows

u_gpu = gpuarray.empty((rows, rows), np.float32)
v_gpu = gpuarray.empty((cols, cols), np.float32)
s_gpu = gpuarray.empty(cols, np.float32)
devInfo = gpuarray.zeros(1, np.int32)

handle = cusolver.cusolverDnCreate()

worksize = cusolver.cusolverDnSgesvd_bufferSize(handle, rows, cols)
print("SIZE", worksize)

Workspace = gpuarray.empty(worksize, np.float32)

svd_status = cusolver.cusolverDnSgesvd(
    handle=handle,
    jobu='A',
    jobvt='A',
    m=rows,
    n=cols,
    A=a_gpu.ptr,
    lda=rows,
    S=s_gpu.ptr,
    U=u_gpu.ptr,
    ldu=rows,
    VT=v_gpu.ptr,
    ldvt=cols,
    Work=Workspace.ptr,
    Lwork=worksize,
    rwork=Workspace.ptr,
    devInfo=devInfo.ptr
)
status = cusolver.cusolverDnDestroy(handle)

我遇到了一个新错误

Traceback (most recent call last):
  File "/home/vektor/PycharmProjects/yancut/test_svd.py", line 53, in <module>
    devInfo=devInfo.ptr
  File "/home/vektor/anaconda3/lib/python3.4/site-packages/skcuda/cusolver.py", line 579, in cusolverDnSgesvd
    Lwork, int(rwork), int(devInfo))
ctypes.ArgumentError: argument 2: <class 'TypeError'>: wrong type

现在看来我对 devInfo 做错了什么

4

1 回答 1

2

从文档看来，每个矩阵（so A, S, U, VT）都需要作为设备指针传递。所以对于 PyCUDA gpuarrays，传递A.ptr而不是A. 等，它应该工作。

于 2015-10-30T12:22:49.957 回答