The CLR has two different kinds of arrays: vectors which are guaranteed to be one-dimensional with a lower bound of 0, and more general arrays which can have non-zero bounds and a rank other than 0. From section 8.9.1 of the CLI spec: Additionally, a created vector with element type T, implements the interface System.Collections.Generic.IList<U> … Read more
First off, there’s been a lot of past discussion about this on the numpy list. For example, see: http://numpy-discussion.10968.n7.nabble.com/poor-performance-of-sum-with-sub-machine-word-integer-types-td41.html http://numpy-discussion.10968.n7.nabble.com/odd-performance-of-sum-td3332.html Some of boils down to the fact that einsum is new, and is presumably trying to be better about cache alignment and other memory access issues, while many of the older numpy functions focus on … Read more
Both array() and the stdClass objects can be accessed using the current() key() next() prev() reset() end() functions. So, if your object looks like object(stdClass)#19 (3) { [0]=> object(stdClass)#20 (22) { [“id”]=> string(1) “123” etc… Then you can just do; $id = reset($obj)->id; //Gets the ‘id’ attr of the first entry in the object If … Read more
Java doesn’t have “true” multidimensional arrays. For example, arr[i][j][k] is equivalent to ((arr[i])[j])[k]. In other words, arr is simply an array, of arrays, of arrays. So, if you know how arrays work, you know how multidimensional arrays work! Declaration: int[][][] threeDimArr = new int[4][5][6]; or, with initialization: int[][][] threeDimArr = { { { 1, 2 … Read more
The memory belonging to a Numpy array must be contiguous. If you allocated the arrays separately, they are randomly scattered in memory, and there is no way to represent them as a view Numpy array. If you know beforehand how many arrays you need, you can instead start with one big array that you allocate … Read more
No, there are no technical reasons why a numpy-like package does not exist for Node.js and, more generally, JavaScript. There are two main obstacles preventing Node.js and JavaScript from achieving more mind share in the data science and numeric computing communities. The first obstacle is community. While the JavaScript community is huge, the subset of … Read more
string[,] Tablero = new string[3,3]; You can also instantiate it in the same line with array initializer syntax as follows: string[,] Tablero = new string[3, 3] {{“a”,”b”,”c”}, {“d”,”e”,”f”}, {“g”,”h”,”i”} };
You can use linear indexing to access each element. for idx = 1:numel(array) element = array(idx) …. end This is useful if you don’t need to know what i,j,k, you are at. However, if you don’t need to know what index you are at, you are probably better off using arrayfun()
You want the GetLength() method of your array: a.GetLength(0); http://msdn.microsoft.com/en-us/library/system.array.getlength.aspx
matrix.GetLength(0) -> Gets the first dimension size matrix.GetLength(1) -> Gets the second dimension size