Python correctly interprets the code as if you used additional variables, so the swapping code is equivalent to: t1 = b[:,0,0] t2 = a[:,0,0] a[:,0,0] = t1 b[:,0,0] = t2 However, even this code doesn’t swap values correctly! This is because Numpy slices don’t eagerly copy data, they create views into existing data. Copies are … Read more
Since the number of columns is a constant, you can just have an List of int[]. import java.util.*; //… List<int[]> rowList = new ArrayList<int[]>(); rowList.add(new int[] { 1, 2, 3 }); rowList.add(new int[] { 4, 5, 6 }); rowList.add(new int[] { 7, 8 }); for (int[] row : rowList) { System.out.println(“Row = ” + Arrays.toString(row)); … Read more
A nice way would be to create a generic/extension method to split any array. This is mine: /// <summary> /// Splits an array into several smaller arrays. /// </summary> /// <typeparam name=”T”>The type of the array.</typeparam> /// <param name=”array”>The array to split.</param> /// <param name=”size”>The size of the smaller arrays.</param> /// <returns>An array containing smaller … Read more
No. You could of course write a wrapper class that represents a slice, and has an indexer internally – but nothing inbuilt. The other approach would be to write a method that makes a copy of a slice and hands back a vector – it depends whether you want a copy or not. using System; … Read more
but it seems that this is really not what one might have expected. Why? Consider that the form T[] means “array of type T”, then just as we would expect int[] to mean “array of type int”, we would expect int[][] to mean “array of type array of type int”, because there’s no less reason … Read more
For me (using Java 1.6.0_26), the first snippet gives the same exception as the second one. The reason is that the Arrays.asList(..) method does only return a List, not necessarily an ArrayList. Because you don’t really know what kind (or implementation of) of List that method returns, your cast to ArrayList<String> is not safe. The … Read more
The answer is not simple. The following is extracted from section 3.2.2 of RFC 3986 : A host identified by an Internet Protocol literal address, version 6 [RFC3513] or later, is distinguished by enclosing the IP literal within square brackets (“[” and “]”). This is the only place where square bracket characters are allowed in … Read more
(pseudo-code) row_limit = count(array); if(row_limit > 0){ column_limit = count(array[0]); for(x = max(0, i-1); x <= min(i+1, row_limit); x++){ for(y = max(0, j-1); y <= min(j+1, column_limit); y++){ if(x != i || y != j){ print array[x][y]; } } } } Of course, that takes almost as many lines as the original hard-coded solution, but … Read more
Summary: If you have a multidimensional array defined as int [][], then x = y[a][b] is equivalent to x = *((int *)y + a * NUMBER_OF_COLUMNS + b); Boring Details: The (int *) cast of y above deserves some explanation, as its necessity may not be at-first intuitive. To understand why it must be there … Read more
It’s clear you’re using numpy. With numpy you can just do: for cell in self.cells.flat: do_somethin(cell)