What
We Have Learned So Far About ArcGIS 8.1
Corvallis
Forest Science Lab GIS Community
April
2001
ArcCatalog:
General
notes: Be careful what you connect to. This can slow your performance
down. Connect to workspaces. Sometimes the copy/paste doesn’t work.
People have not had as much trouble with the drag and drop. Dragging files to a directory where you
don’t have permissions can be a problem. Files have been deleted instead of
falling back into the original directory.
Remember
to right click on a coverage/shapefile for more options.
Metadata:
you will have to create a template of your repeating information to load before
you add other data. Remember that you
can do metadata for anything with this tool. It’s pretty handy. You can
document a workspace/file/picture/image, whatever. You have to connect your metadata to something (coverage, text
file, some object). The raw xml files need to be with the item they are
documenting.
ArcCatalog
is where you define items, update item characteristics, delete items. You do
this in a properties menu and if you change your mind about a change, you can
cancel the changes before you hit apply.
You
can define what types of files you want to view by opening the Tools menu, select options and make the changes in the
popup window under file types. You can add text files, documents, etc.
You
can change your defaults for metadata here also. One exciting change to make is
to add fields to your contents tab. From the contents tab, add metadata fields
to view. This will give you more information when you browse the catalog.
We
have been having problems when arccatalog is open and arcmap or toolbox. We
sometimes get ‘same user’ errors and have to exit all the way out of arcgis
before we can continue. (Had this problem recently with adding a second field
to a coverage).
ArcMap
ArcMap
acts like arcview, but uses different tools. You don’t have projects and you
only have one layout per map layer. You
can document these map layers in arc catalog.
Some problems with printing (you need to specify your default printer as
a postscript. You don’t have to use that printer, but it needs to be set up
that way). Also, what you see is not
what you always get. You have to play
with it, but sometimes you can make a layout that won’t print the way you set
it up. Not sure when they’ll fix
this. I have not been able to get a
large map with a DOQ printed using this tool.
Using arcpress from arcmap can cause your computer to be tied up for
hours and hours (where you can’t do any other work). I have been sending my
files through arcpress on the Unix side because I can then continue working on
my PC.
When
you want to create or open another map in ArcMap, you have to close the session
you were working in (you can’t minimize it like you would in other programs).
This can be a pain in the neck when you want to toggle back and forth between
two map sessions.
All the arcedit-like functions and the
analysis processes for the geodatabase are found in ArcMap. We found that if you edit a coverage and
save edits, the coverage will be cleaned and renoded. You won’t be asked if you want this done, it just happens.
Converting
ArcView projects into ArcMap. There is
an import function for converting ArcView projects into a mxd file (map layer?).
You can only bring in one layout at a time.
If you have multiple layouts in your project files, you can import them
one layout at a time (the wizard asks you to select a layout). Most likely people who want to convert will
need to clean up their projects before they import.
We
are having problems adding multiple geodatabase raster themes into ArcMap at
the same time (using multi-selects or drag and drop). Currently they need to be
added one at a time. This has been
reported to ESRI.
Sometimes
you’ll have images that should be showing on your map that don’t when you go
back into ArcMap. I have reset the source (layer properties) even though it
appears correct and this fixes the problem.
This has also been reported to ESRI.
Working
with quantities for displaying ranges of data.
I could not get certain values to disappear (0) and I even tried using
the query builder to exclude 0, but it kept coming back in my legend (I would
change the values and it would put the 0 back in). What finally worked was using the exclusion button on the
symbology tab (with quantities selected) and I was able to exclude a
value. This was the only way I could
get rid of the value I didn’t want to show on my map. It was not very intuitive
and took us a while to figure it out.
Inserted
background boxes do not show up when you print. You can go to View, Data Frame
Properties and go to the Frame tab to change the background of your map. You can also go to the Grids tab to add grid
lines or graduals.
ArcMap
will project your coverages 'on the fly' when you add them to your map session.
You might think this is a good thing, and sometimes it could be. It can be a bad thing if you aren't paying
attention that your coverages are in different projections and you later want
to do some analysis (a union, buffer, etc). It also makes it near to impossible
to figure out what projection a coverage is in if there isn't a projection
file. It might just come up looking like it's fine...so you could assume it's
in the same projection as your other data when in fact, ArcMap is projecting
it. You can look in the metadata, but
if no projection is defined, you are in trouble.
The
plus: It's great for display, not to have to project coverages. You don't even really need to understand
anything about projections.
The
minus: You will be in trouble when you
try to do any type of analysis unless you understand that your data could be in
a different projection. You will have to use other means to figure out what the
heck projection this coverage is in. (or shape file). People who don't
understand projections (most first time users from my experience) will be able
to make great maps, but won't understand the importance of or role of
projections.
Another
point is that you can define this to be any projection you want (even if it's
wrong). It's real easy to do with the menus.
One
last point is that the first coverages/shape file/feature type that you enter
into your map session, will define the projection of the session. All other data will be projected to match
that first thing you entered. You need
to keep this in mind when you are bringing data into your session.
I
think they need a big 'WARNING...WE ARE PROJECTING THIS DATA TO MATCH THE
EXISTING DATA' when data is importing into the session.
ArcToolbox:
In
General: full wizards work better than non wizards (more options). Analysis tools do not cover analysis within
a geodatabase. That is done in ArcMap.
Need to be careful what modules you have open when dealing with the
personal geodatabase or with coverages.
Projection tools are cool. You can project to another coverage/shapefile
and the software will automatically read the projection file from the
coverages/shapefiles. Some folks have
also used the wizards to write amls to automate tasks.
You
need to have workstation ARC/INFO loaded onto your PC to use ArcToolbox. It
actually is performing many command line functions.
Geodatabases:
Personal
Geodatabases: no additional hardware/software needed, uses access, must be
careful about what modules you have open because of one user conflicts, can’t
do raster, good for exploring how to use the geodatabases.
SDE
Geodatabases: need additional software
(RDBMS), can put rasters into them,
allows multiple users, can grab data from other locations faster (don’t
have to mount the drives, just need access to them).
We
have not looked at why you would want to convert your data to a
geodatabase. This is the topic of an
upcoming session.
When
you convert you data to a geodatabase you have to be careful not to use the
area and perimeter (or length) fields anymore if you edit the data. You will
have new items for area/perimeter/length at the end of the attribute table.
These fields will be updated as you edit the data in your geodatabase. The area /length/perimeter fields will not
be updated and should be removed to eliminate confusion.
Metadata
did not transfer when we converted a coverage with a metadata file (xml) into a
geodatabase. We had to import it in
after we converted.
What
happens when we convert data back into a coverage or exchange file per request
from other folks?
ArcView
8.1. ArcView 8.1 is a subset of ArcGIS
8.1. It will have the same look and feel, but not all the functionality of
ArcGIS. You can not have ArcGIS and
ArcView 8.1 on the same machine. You
can have ArcGIS and ArcView 3.x on the same machine
We
have not tested ArcView 8.1
Raster
Processing within a Geodatabase with SQL Server:
Speed
is very slow. Takes up all the speed of the CPU. Can we send a job to
another CPU? Does that CPU need to have arc8.1 loaded?
When
there are more that 256 values. What happens to your data? We get an error but not sure what happens.
We
could not add fields to the geodatabase (with Rasters). The error was: Failed
to add the field to the table/feature class.
Some
no-data fields were changed to zero.
DEM
data had negative numbers.
Question
about the advantage of duel processors?
We have heard that ArcGIS is a single processor program. What would having a duel processor buy us?