multidimensional-array
Multidimensional Arrays lengths in Java
This will give you the length of the array at index i pathList[i].length It’s important to note that unlike C or C++, the length of the elements of a two-dimensional array in Java need not be equal. For example, when pathList is instantiated equal to new int[6][], it can hold 6 int [] instances, each … Read more
Java: Multi-dimensional array vs. one-dimensional
Usually the best thing to do when searching anwers for such questions is to see how the choices are compiled into JVM bytecode: multi = new int[50][50]; single = new int[2500]; This is translated into: BIPUSH 50 BIPUSH 50 MULTIANEWARRAY int[][] 2 ASTORE 1 SIPUSH 2500 NEWARRAY T_INT ASTORE 2 So, as you can see, … Read more
Omitting Sizes while Initializing C/C++ Multidimensional Arrays
The following is from section A8.7 of “The C Programming Language” by K&R, 2nd edition, pages 219,220: An aggregate is a structure or array. If an aggregate contains members of aggregate type, the initialization rules apply recursively. Braces may be elided in the initialization as follows: if the initializer for an aggregate’s member that is … Read more
How to convert a 3d numpy array to 2d
In [27]: x = np.arange(16).reshape((4,2,2)) In [28]: x.reshape(2,2,2,2).swapaxes(1,2).reshape(4,-1) Out[28]: array([[ 0, 1, 4, 5], [ 2, 3, 6, 7], [ 8, 9, 12, 13], [10, 11, 14, 15]]) I’ve posted more general functions for reshaping/unshaping arrays into blocks, here.
Printing 2D array in matrix format
You can do it like this (with a slightly modified array to show it works for non-square arrays): long[,] arr = new long[5, 4] { { 1, 2, 3, 4 }, { 1, 1, 1, 1 }, { 2, 2, 2, 2 }, { 3, 3, 3, 3 }, { 4, 4, 4, 4 } … Read more