I would use Update Column from the Table menu. MI allows you to take data
from "hidden" fields and transfer it to viewable columns. These are the
same data fields that report the area of a region when you double click on
it. I needed to update my parcel table so I went ahead and did this. Below
is the text copied from the mapbasic window after I completed the dialogue
boxes from SQL select and Update Column. My parcel table already has a
field to hold the area data, called Estimated_Acres. You should have (add)
a column in your table to hold the area data you will be taking from MI.
Select * from Parcels where RecordStatus = "A" into Selection
Browse * From Selection
My parcel table contains other objects, such as notes, old subdivision plat
lines that are no longer property lines, etc. so I selected only the objects
that have an "A" (for active) from the RecordStaus Field, this became
Query3. I had to work from this query because I encountered an error msg
when I tried to directly update the column with the area function, I assumed
that MI didn't like the other objects in the table.
Add Column "Query3" (Area_obj___acre__ Float)From Parcels Set To Area(obj,
"acre") Where COL1 = COL1 Dynamic
Browse * From Query3
This was scripted from the Table menu>Update Column (above). You are adding
a temp column to Query 3 that will be the value of the expression Area(obj,
"acre") from the parcel table (the parent of query3), you could use "sq mi"
instead of "acre"
Update Query3 Set Estimated_Acres = Area_obj___acre__
Browse * From Query3
This transfers the data in the temp column to the permanent column
Estimated_Acres. Its called Estimated because it's the area as drawn -
misdrawn parcels produce inaccurate areas
William Woodruff
Zoning Administrator
Charter Township of Union, T14 N R4W, Isabella County, Michigan
(517) 772 4600 ext 41, FAX (517) 773 1988
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
Behalf Of David Eagle
Sent: Wednesday, April 26, 2000 12:01 PM
To: Lathrop, Travis
Cc: [EMAIL PROTECTED]
Subject: Re: MI Date: Wed, 26 Apr 2000 10:02:26 -0500
Travis,
Go to the drop down menu Map and then select Options at the
bottom of the menu...Change the Area Units to Square Miles and
select OK.
Now in your Mapper select the polygon in question, then click on
the drop down menu Edit and then Get Info, again at the bottom of
the menu...There's your answer, hope that helps...
Dave
On 26 Apr 00, at 9:02, Lathrop, Travis wrote:
How would one go about calculating the total area, sq. mi, a polygon
represents. I have dug in the help file looking at the area function with
little success.
Travis Lathrop
Intercarrier Services
(816) 559-3014
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_________________________________________________________
David A. Eagle
WS Atkins Consultants - East Anglia
Wellbrook Court, Girton Road, Cambridge, CB3 0NA.
Direct Dial Tel: (01223) 814090, Fax: (01223) 277529
E-Mail: [EMAIL PROTECTED]
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