Map[titude will allow a one-to-many join if you have a layer to
begin with that has all the points in your data. But in order to prepare that
point coverage you will need to identify all the unique points in your data,
requires using SAS or similar and set up a label for them in your point coverage
and in your data. Each unique combination of long/lat will need a unique
identifier.
However, I think you should do all the calculations in SAS
(SPSS)
If your data looks like this and is contained in a file
mydata.sd2
long lat var1 var2 ....
varn
Where there may be duplicates of long, lat or
libname input "c:\temp\" ; * location of the data mydata.sd2 ;
proc freq data=input.mydata; tables
long*lat/out=input.mapt;
run;
This will produce a file mapt.sd2 in the director referred to
in libname which will have the following
structure: (you will need to convert the SAS file into
something Mapt can use, dbf or Excel.
obs long lat count percent
obs is the observation number, and
count is the number of records that shared a common
long & lat.
So when you take this files into Maptitude you can use a
graduated point symbol to display the number of records at each point. If you
are using something other than SAS, likely you can get the idea here and
translate.
Richard Hoskins
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
GMT -8
-----Original Message-----
From: kbyrnes [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 11, 2001 5:27 AM
To: [EMAIL PROTECTED]
Cc: Maptitude List Server
Subject: [Maptitude] Thematic Mapping Question
Importance: High
Maptitude - http://research.umbc.edu/~roswell/maptitude.html
I have a file that involves multiple observations (records) at common
locations. Is there a technique in Maptitude for displaying each unique
location and the number of records which share that common location?
As an example, suppose a file of residential addresses included multiple
residents from many different apt. bldgs. as well as lots of records for
single-family homes. The desired map would be the point locations of all
the unique addresses and either:
* a label representing the number of records for each unique location
or
* a thematic symbol at each location representing a range in the
number of records (e.g. 1, 2-5, 6-10, etc.)
I'd appreciate any ideas anyone might have on how to approach this
problem.
Thanks
Kevin Byrnes, Demographer
Virginia Dept. for the Aging
______________________________________________________________________
To unsubscribe, write to [EMAIL PROTECTED]
Richard Hoskins
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
GMT -8
-----Original Message-----
From: kbyrnes [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 11, 2001 5:27 AM
To: [EMAIL PROTECTED]
Cc: Maptitude List Server
Subject: [Maptitude] Thematic Mapping Question
Importance: High
Maptitude - http://research.umbc.edu/~roswell/maptitude.html
I have a file that involves multiple observations (records) at common
locations. Is there a technique in Maptitude for displaying each unique
location and the number of records which share that common location?
As an example, suppose a file of residential addresses included multiple
residents from many different apt. bldgs. as well as lots of records for
single-family homes. The desired map would be the point locations of all
the unique addresses and either:
* a label representing the number of records for each unique location
or
* a thematic symbol at each location representing a range in the
number of records (e.g. 1, 2-5, 6-10, etc.)
I'd appreciate any ideas anyone might have on how to approach this
problem.
Thanks
Kevin Byrnes, Demographer
Virginia Dept. for the Aging
______________________________________________________________________
To unsubscribe, write to [EMAIL PROTECTED]
To unsubscribe, write to [EMAIL PROTECTED]
