Convert data type without changing the bits:

    IDL>   Y = [0.0, 1.0, 1.5, 2.0]
    IDL>   ZZ = long(Y,0,n_elements(Y))   ;"offset" param does the trick
    IDL>   print,ZZ,format='(12x,4(1x,Z8.8))'
               00000000 3F800000 3FC00000 40000000

        -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Cursor stuff:

  Draw Widgets:
  ------------
    tvcurs,onOff
    tvcurs,x,y    ;show cursor at x,y

  Idl Graphics Windows:
  --------------------
    cursor,x,y,WaitOptions
       WaitOptions: 0 : nowait
                    1(default) : button down
                    2 : change (button down/up or pointer moved)
                    3 : button up
       !MOUSE struct: constantly updated.
            {long x ; long y ; long buttonMask ; long time}
                               1=Left 2=Mid 3=Rt     ms_since_basetime