Welcome to a world with Java 8! It only took me all night with no sleep to learn what was needed to write this one freaking line of code. I’m sure it is already out there somewhere but I couldn’t find it. So I’m sharing my hours and hours of research, enjoy. Woot! Assuming: ArrayList<ArrayList<String>> … Read more
You can try this code: public class MyMatrix { Double[][] A = { { 4.00, 3.00 }, { 2.00, 1.00 } }; Double[][] B = { { -0.500, 1.500 }, { 1.000, -2.0000 } }; public static Double[][] multiplicar(Double[][] A, Double[][] B) { int aRows = A.length; int aColumns = A[0].length; int bRows = B.length; … Read more
Yes. However, it doesn’t work the way you are thinking it works. Rather, it thinks of each mutlidimensional array as a single-dimensional array (which is actually what they are in memory, it’s just a trick that lets us place some structure on top of them to think of them as multidimensional) and then copies the … Read more
Try the partition method @arr1, @arr2 = @level1.partition { |x| x[0] > 2.1 } The condition there may need to be adjusted, since that wasn’t very well specified in the question, but that should provide a good starting point.
I want to create a 2D array that each cell is an ArrayList! If you want to create a 2D array of ArrayList.Then you can do this : ArrayList[][] table = new ArrayList[10][10]; table[0][0] = new ArrayList(); // add another ArrayList object to [0,0] table[0][0].add(); // add object to that ArrayList
The C# compiler thinks you’re trying to declare a jagged array, and doing so incorrectly. A jagged array is an array of arrays, where each array contained within the main array can have a different number of elements. A jagged array is declared as follows: int[][] jaggedArray = new int[numElements][]; Which would create an array … Read more
you can do this in two simple steps using NumPy: >>> # multiply column 2 of the 2D array, A, by 5.2 >>> A[:,1] *= 5.2 >>> # assuming by ‘cumulative sum’ you meant the ‘reduced’ sum: >>> A[:,1].sum() >>> # if in fact you want the cumulative sum (ie, returns a new column) >>> … Read more