How to initilize thrust device vector from another device vector declared by cuda

[ztdepztdep]

I have a device vector d_b[100], I want to creat a thrust vector with d_b[80:100]. How to resolve this mission.

[miscco]

I am not fully sure what you mean with d_b[80:100]

However, you could always use one of the algorithms such like https://github.com/NVIDIA/thrust/blob/main/thrust/fill.h

[ztdepztdep]

I am not fully sure what you mean with d_b[80:100]

However, you could always use one of the algorithms such like https://github.com/NVIDIA/thrust/blob/main/thrust/fill.h

I mean fill thrust vector with d_b from the 80'th to the 100'th values.

[miscco]

In that case you would need to use thrust::copy or thrust::copy_n You can find some documentation here

thrust/thrust/copy.h

Lines 118 to 130 in 125d281

	* \code
	* #include <thrust/copy.h>
	* #include <thrust/device_vector.h>
	* #include <thrust/execution_policy.h>
	* ...
	* size_t n = 100;
	* thrust::device_vector<int> vec0(n);
	* thrust::device_vector<int> vec1(n);
	* ...
	* thrust::copy_n(thrust::device, vec0.begin(), n, vec1.begin());
	*
	* // vec1 is now a copy of vec0
	* \endcode

[pauleonix]

If possibe, I would rather just use the right constructor to avoid unnecessary initialisation, i.e.

thrust::device_vector<float> d_c(d_b.cbegin() + 80, d_b.cend());
// or
thrust::device_vector<float> d_c(d_b.cbegin() + 80, d_b.cbegin() + 100);

[Pavelevich]

this can work for u:

• device vector is already with some values

int main()
{
int size = 299;
int d_b[299];
thrust::device_vector d(d_b, d_b + size);
thrust::device_ptr d_ptr = thrust::make_device_ptr(d_b);
thrust::device_vector d_subset(d_ptr + 66, d_ptr + 299);
return 0;
}