From c572cc902033600dbd38424ba7982d5da0b4bde6 Mon Sep 17 00:00:00 2001
From: Pauli Virtanen <pauli.t.virtanen@jyu.fi>
Date: Tue, 2 Aug 2022 15:18:37 +0300
Subject: [PATCH] Slicing
---
src/action.hpp | 9 +++--
src/array.hpp | 105 +++++++++++++++++++++++++++++++++++++++++++++++++
src/common.hpp | 50 +----------------------
src/main.cpp | 18 +++------
4 files changed, 119 insertions(+), 63 deletions(-)
create mode 100644 src/array.hpp
diff --git a/src/action.hpp b/src/action.hpp
index 6d9127f..c8c57b4 100644
--- a/src/action.hpp
+++ b/src/action.hpp
@@ -2,12 +2,15 @@
#define ACTION_HPP_
#include "common.hpp"
+#include "array.hpp"
-inline ADComplex S_2(Array<ADComplex,3> Q)
+template <typename Scalar>
+inline Scalar S_2(Array<Scalar,2> Q)
{
- size_t i = 2;
- return Q(0u, i, 2u);
+ Q(0u,0u) = 123;
+ Q(1u,1u) = 123;
+ return 0;
}
diff --git a/src/array.hpp b/src/array.hpp
new file mode 100644
index 0000000..672fed9
--- /dev/null
+++ b/src/array.hpp
@@ -0,0 +1,105 @@
+#ifndef ARRAY_HPP_
+#define ARRAY_HPP_
+
+/*! Simple data-by-reference strided array class
+ */
+template <typename Scalar, int NDim>
+class Array
+{
+private:
+ std::vector<Scalar>& data_;
+ std::array<size_t, NDim> shape_;
+ std::array<size_t, NDim> stride_;
+ size_t offset_ = 0;
+
+public:
+ Array(Array<Scalar,NDim>&& array)
+ : data_(array.data_), shape_(array.shape_), stride_(array.stride_), offset_(array.offset_)
+ {}
+
+ Array(std::vector<Scalar>& data, const std::array<size_t, NDim> shape, const std::array<size_t, NDim> stride, const size_t offset=0)
+ : data_(data), shape_(shape), stride_(stride), offset_(offset)
+ {}
+
+ Array(std::vector<Scalar>& data, const std::array<size_t, NDim> shape)
+ : data_(data), shape_(shape), offset_(0)
+ {
+ // row-major strides
+ for (size_t i = NDim; i > 0; --i) {
+ if (i == NDim)
+ stride_[i-1] = 1;
+ else
+ stride_[i-1] = shape[i] * stride_[i];
+ }
+ }
+
+ template <typename... Idx>
+ Scalar& operator()(Idx... idxs) { return data_[index(idxs...)]; }
+
+ template <typename... Idx>
+ const Scalar&& operator()(Idx... idxs) const { return data_[index(idxs...)]; }
+
+ template <size_t axis>
+ Array<Scalar, NDim-1> slice(size_t pos=0) const
+ {
+ std::array<size_t, NDim-1> shape;
+ std::array<size_t, NDim-1> stride;
+ size_t offset;
+
+ offset = stride[axis] * pos;
+
+ for (size_t i = 0, j = 0; i < NDim; ++i) {
+ if (i == axis)
+ continue;
+ shape[j] = shape_[i];
+ stride[j] = stride_[i];
+ ++j;
+ }
+
+ return Array<Scalar,NDim-1>(data_, shape, stride, offset);
+ }
+
+ template <size_t axis>
+ Array<Scalar, NDim> slice(size_t begin, size_t end) const
+ {
+ std::array<size_t, NDim> shape;
+ std::array<size_t, NDim> stride;
+ size_t offset;
+
+ offset = stride[axis] * begin;
+
+ for (size_t i = 0; i < NDim; ++i) {
+ if (i == axis)
+ shape[i] = end - begin;
+ else
+ shape[i] = shape_[i];
+ stride[i] = stride_[i];
+ }
+
+ return Array<Scalar,NDim>(data_, shape, stride, offset);
+ }
+
+ std::vector<Scalar>& data() { return data_; }
+
+ template <size_t axis>
+ const size_t shape() const { return shape_[axis]; }
+
+ template <size_t axis>
+ const size_t stride() const { return stride_[axis]; }
+
+ size_t offset() const { return offset_; }
+
+ template <typename... Idx>
+ size_t index(Idx... idxs) const
+ {
+ const std::array<size_t, NDim> m{idxs...};
+ size_t idx = offset_;
+
+ for (size_t i = 0; i < NDim; ++i)
+ idx += stride_[i] * m[i];
+
+ return idx;
+ }
+};
+
+#endif
diff --git a/src/common.hpp b/src/common.hpp
index 12d7b98..0aac231 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -1,5 +1,5 @@
-#ifndef COMMON_H_
-#define COMMON_H_
+#ifndef COMMON_HPP_
+#define COMMON_HPP_
#include <array>
#include <tuple>
@@ -13,50 +13,4 @@
typedef CppAD::AD<double> ADDouble;
typedef std::complex<ADDouble> ADComplex;
-template <typename Scalar, int NDim>
-class Array
-{
-private:
- std::vector<Scalar>& data_;
- std::array<size_t, NDim> shape_;
- std::array<size_t, NDim> stride_;
-
-protected:
- template <typename... Idx>
- size_t index(Idx... idxs) const
- {
- const std::array<size_t,NDim> m{idxs...};
- size_t idx = 0;
-
- for (size_t i = 0; i < NDim; ++i)
- idx += stride_[i] * m[i];
-
- return idx;
- }
-
-public:
- Array(std::vector<Scalar>& data, std::array<size_t, NDim> shape) : data_(data), shape_(shape)
- {
- if (NDim > 0) {
- size_t i = NDim - 1;
- stride_[i] = 1;
- while (i-- > 0)
- stride_[i] = shape[i+1] * stride_[i+1];
- }
- }
-
- template <typename... Idx>
- Scalar& operator()(Idx... idxs)
- {
- return data_[index(idxs...)];
- }
-
- template <typename... Idx>
- const Scalar&& operator()(Idx... idxs) const
- {
- return data_[index(idxs...)];
- }
-};
-
-
#endif
diff --git a/src/main.cpp b/src/main.cpp
index 7d79f02..9a79fdc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,20 +4,14 @@
int main()
{
- std::vector<double> v(3*3*3);
- Array<double,3> Q(v,{3,3,3});
+ std::vector<double> v(2*2*2);
+ Array<double,3> Q(v,{2,2,2});
- for (size_t i = 0; i < 3; ++i) {
- for (size_t j = 0; i < 3; ++i) {
- for (size_t k = 0; i < 3; ++i) {
- Q(i,j,k) = i+j+k;
- }
- }
- }
+ S_2(Q.slice<3>());
- for (size_t i = 0; i < 3; ++i) {
- for (size_t j = 0; i < 3; ++i) {
- for (size_t k = 0; i < 3; ++i) {
+ for (size_t i = 0; i < Q.shape<0>(); ++i) {
+ for (size_t j = 0; j < Q.shape<1>(); ++j) {
+ for (size_t k = 0; k < Q.shape<2>(); ++k) {
std::cout << Q(i,j,k) << std::endl;
}
}
--
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