Multi-dimensional arrays

One of the most common storage structures is the array. TBTK therefore has a simple Array class that allows for multi-dimensional data to be stored. Such an Array can be created as follows

Array<DataType> array({SIZE_0, SIZE_1, SIZE_2});

where DataType should be replace by the specific data type of interest. While the code above will create a three-dimensional array with dimensions (SIZE_0, SIZE_1, SIZE_2), it is possible to pass an arbitrary number of arguments to the constructor to create an Array of any dimension.

By default an array is uninitialized at creation, but it is possible to also supply a second argument at creation that will be used to initialize each element in the array. For example, it is possible to initialize a three-dimensional array of doubles with zeros in the following way

Array<double> array({SIZE_0, SIZE_1, SIZE_2}, 0);

Once created it is possible to access the ranges of the array using

const vector<unsigned int> &ranges = array.getRanges();

An individual element in the Array can be accessed using

DataType &data = array[{x, y, z}];

where 0 <= x < ranges[0], 0 <= y < ranges[1], and 0 <= z < ranges[2].

Given that the DataType supports the corresponding operators, it is also possible to add and subtract arrays from each other

Array<DataType> sum = array0 + array1;
Array<DataType> difference = array0 - array1;

as well as multiply and divide them by an element of the given DataType

Array<DataType> product = element*array;
Array<DataType> quotient = array/element;

A subset of an Array can also be extracted using

Array<DataType> array2D = array.getSlice({x, _a_, _a_});

which in this case will extract the two-dimensional slice of the Array for which the first index is 'x'. The new array is a pure two-dimensional array from which elements can be extracted using

DataType &element = array2D[{y, z}];