You can’t do what you’re trying to do: bash arrays are one-dimensional $ declare -A PERSONS $ declare -A PERSON $ PERSON[“FNAME”]=’John’ $ PERSON[“LNAME”]=’Andrew’ $ declare -p PERSON declare -A PERSON='([FNAME]=”John” [LNAME]=”Andrew” )’ $ PERSONS[1]=([FNAME]=”John” [LNAME]=”Andrew” ) bash: PERSONS[1]: cannot assign list to array member You can fake multidimensionality by composing a suitable array index … Read more
You can use np.where to return a tuple of arrays of x and y indices where a given condition holds in an array. If a is the name of your array: >>> np.where(a == 1) (array([0, 0, 1, 1]), array([0, 1, 2, 3])) If you want a list of (x, y) pairs, you could zip … Read more
You can use a type alias template: #include <array> #include <cstddef> template <class T, std::size_t x, std::size_t y> using Array2D = std::array<std::array<T, y>, x>; int main() { Array2D<int, 5, 3> arr; } You can also generalize it like so for any dimension: #include <array> #include <cstddef> template <class T, std::size_t size, std::size_t… sizes> struct ArrayHelper … Read more
Like this: int main() { int arr[2][5] = { {1,8,12,20,25}, {5,9,13,24,26} }; } This should be covered by your C++ textbook: which one are you using? Anyway, better, consider using std::vector or some ready-made matrix class e.g. from Boost.
int a[2][3]; a is read as an array 2 of array 3 of int which is simply an array of arrays. When you write, int (*p)[3] = a; It declares p as a pointer to the first element which is an array. So, p points to the array of 3 ints which is a element … Read more
This code returns a 2d array. #include <cstdio> // Returns a pointer to a newly created 2d array the array2D has size [height x width] int** create2DArray(unsigned height, unsigned width) { int** array2D = 0; array2D = new int*[height]; for (int h = 0; h < height; h++) { array2D[h] = new int[width]; for (int … Read more
The purpose of meshgrid is to create a rectangular grid out of an array of x values and an array of y values. So, for example, if we want to create a grid where we have a point at each integer value between 0 and 4 in both the x and y directions. To create … Read more
I’d go for the first option (the single 1D array) as it will give you a single block of memory to play in rather than potentially thousands of fragmented memory blocks If accessing the correct element of the array is doing your head in though, I’d write a utility method to convert x, y, z … Read more
No. A double** is a pointer to a pointer to a double (double*). So actually it should be created like this (note the extra * in the first malloc sizeof()): double** result = (double**) malloc(sizeof(double*)*4); for (int i = 0; i < 4; i++) { result[i] = (double*) malloc(sizeof(double)*4); } So in memory it would … Read more
Input In [12]: aten = torch.tensor([[1, 2, 3], [4, 5, 6]]) In [13]: aten Out[13]: tensor([[ 1, 2, 3], [ 4, 5, 6]]) In [14]: aten.shape Out[14]: torch.Size([2, 3]) torch.view() reshapes the tensor to a different but compatible shape. For example, our input tensor aten has the shape (2, 3). This can be viewed as … Read more