Setting Map Size
MICRODEM opens maps with what it considers to be a reasonable set of
default settings, showing the entire data set on screen without scrollbars.
There can be two sets of scrollbar, one for the main program area, and one for a
map, which can be particularly confusing since parts of the maps can be hiding
off screen.
- This will always be a compromise, and much of learning to use GIS means
understanding these settings and how they should be modified for a
particular task. Screen size is almost always insufficient to show the
full resolution a data set and its full extent at the same time.
- You will likely not initially see the full detail in
the data set, and should reserve judgment on the quality of the data until
you have looked at the data at full resolution.
1:1
map view will show the best resolution view of
the data, but might strain your system and force you to use the
scrollbars and challenge you find the region of interest.
-
Zoom in (makes the map larger with the same coverage area)
-
Zoom out (makes the map smaller with the same
coverage area)
Subset
& zoom is a good option before going to the 1:1 view.
If you only want to use a small region of the DEM, you can
save just the map subset map area.- The original size of the maps is set on the Options,
Maps tab, and you can increase this default if you
want bigger maps (or get a 4K monitor). The map size selected here
will be used for DEMs and imagery. One of the values will be adjusted
down to keep the aspect ratio of the map. A setting on
Options, Vector maps
tab sets the size for vector maps.
- For DEM maps there is a second option:
- Options,
Maps tab, set a zoom factor, with the check box
and edit box (Maps
tab). 100% is 1:1 view,
50% is every other column in every other row, and so on. If the data
spacing is unequal, such as in a lat/long DEM, this will be approximate to
keep the correct aspect ratio of the map. If you have a big DEM, this
can be slow and laborious to maneuver.
Information on the map will show you when
the data has to be subsampled to show on screen, or if the program is
interpolating to a finer resolution.- The Modify, Map size menu choice
lets you change the map size.
- The File, Match other maps menu
choice lets you have all the open maps have the same coverage area and
scaling, if they cover the same area..
Last revised 9/17/2018