slice

Slice an operator with new start and end points, and optionally new strides. Slice can also be used to drop ranks, for operations such as selecting a single row. Negative indices can be used to indicate starting at the end and going backward.

template<int N, typename OpType>
__MATX_INLINE__ auto matx::slice(const OpType opIn, const index_t (&starts)[OpType::Rank()], const index_t (&ends)[OpType::Rank()])

template<int N, typename OpType>
__MATX_INLINE__ auto matx::slice(const OpType op, const index_t (&starts)[OpType::Rank()], const index_t (&ends)[OpType::Rank()], const index_t (&strides)[OpType::Rank()])

Examples

auto t2 = make_tensor<TestType>({20, 10});
auto t3 = make_tensor<TestType>({30, 20, 10});
auto t4 = make_tensor<TestType>({40, 30, 20, 10});

(t2 = linspace<1>(t2.Shape(), (inner_type)0, (inner_type)10)).run(exec);
(t3 = linspace<2>(t3.Shape(), (inner_type)0, (inner_type)10)).run(exec);
(t4 = linspace<3>(t4.Shape(), (inner_type)0, (inner_type)10)).run(exec);
cudaStreamSynchronize(0);

// Slice with different start and end points in each dimension
auto t2t = slice(t2, {1, 2}, {3, 5});
auto t3t = slice(t3, {1, 2, 3}, {3, 5, 7});
auto t4t = slice(t4, {1, 2, 3, 4}, {3, 5, 7, 9});

auto t1 = make_tensor<TestType>({10});

t1.SetVals({10, 20, 30, 40, 50, 60, 70, 80, 90, 100});

// Slice every other element from a 1D tensor (stride of two)
auto t1t = slice(t1, {0}, {matxEnd}, {2});

// Slice "t2t" by selecting column "j" from a 2D operator and converting to a 1D operator
auto t2sly = slice<1>(t2t, {0, j}, {matxEnd, matxDropDim});

auto t2sn = slice(t2, {-4, -5}, {matxEnd, matxEnd});
auto t2s = slice(t2, {t2.Size(0) - 4, t2.Size(1) - 5}, {matxEnd, matxEnd});