An RArray is a struct that holds an n-dimensional array allocated inside R. You can see the functionality it provides by reading this code:
auto arr = RArray(2,3,4,2);
foreach(ii; 0..48) {
arr.ptr[ii] = double(ii);
}arr is a 4-dimensional array with dimensions 2x3x4x2, for 48 total elements. The constructor takes an group of arguments of any length.
printR(arr.x);
writeln(arr);You can print the array using the low-level interface (printR) or the high-level interface (writeln).
writeln(arr[1,1,1,1]);
writeln(arr[1,2,3,1]);
writeln(arr[1,1,3,0]);You can pull out individual elements using the usual notation.
arr[1,1,1,1] = 33.7;You can set elements using the usual notation.
arr = 2.7;You can set all elements of an array to the same value.
arr = rnorm(48);A check will be done to be sure the dimensions match. Since arr has 48 elements, this operation works. This would throw an error:
arr = rnorm(47);You cannot assign to an array incompletely; the above will not fill the first 47 elements of arr.
auto arr2 = arr.sub[0, 0, 0, _all];The combination of a variable number of arguments and multidimensional slicing means you have to create a reference to the array in order to do multidimensional slicing if you want to be able to assign to a multidimensional slice. .sub returns a reference to the array.
auto arr3 = arr.sub[0, 0..3, 0, _all];
arr.sub[0..2, 0, 0, 0] = arr.sub[0..2, 1, 1, 1];_all means all elements on that dimension. 0..2 means the first two elements of that dimension.
auto m = Matrix([1.1, 2, 3, 4, 5, 6], 2, 3);
arr.sub[0..2, 0..3, 1, 1] = m;You can assign other structs, such as a Matrix, to a subset of an array, so long as the dimensions match.