When you click the "Distances" button on the main form, you will see a window displaying the distance between each pair of cities in the data set. At the top of the form, you can choose whether to compute distances or load them from a file. If you want distances to be computed, you can choose whether to use Euclidean or great circle distances. If you want to load them from a file, enter the file name where indicated or click the Browse button to choose a file. You can also request VRP Solver to round all distances to the nearest integer by checking the obvious checkbox. The default (when you first load a data set) is Euclidean distances and no rounding.
If you change an option, the distances will not automatically be recomputed. To compute distances, you must click the "Compute Distances" button. The text below the Preferences box indicates whether the distance matrix as displayed reflects your current settings, or whether the distances need to be recomputed.
You can save the current distance matrix to a text file by clicking the "Save Distances" button.