One can use the IDE to view the exact contents of each item in a GDX file by opening a GDX file with the Open file dialogue. The resultant display gives the names of the items in the GDX file on left hand part of the screen while the right part gives the exact data entries for the item highlighted in the left hand part. Namely opening the file gdxall.gdx and moving the cursor to the set i6 causes the screens to become
showing the elements in the set as contained within the GDX file. Similarly choosing the object modedistance yields the screen
showing the data for this item. The data may be reordered via the mouse. For example placing the mouse on the column containing san francisco and dragging the column up yields
which is the slice of the matrix containing san francisco data. In turn clicking on Brussels yields
Also note that the columns are sortable in the left hand portion of the display. All one needs to do is to click on the gray boxes (Symbol, Type,...) with the mouse. There is also a search dialog at the bottom that permits one to look for select items.
Finally note a right mouse click allows one to write the contents of any or all items to HTML format.