Hello Joan,
Thanks for the tip. I also am trying to measure distance between centroids.
I have tried several syntax commands, that are "correct, but don't produce
results.
Here is a summary of my efforts if someone can help.
Try following steps:
1. Create a point objects from centroids of "Home" and "Out" places --> table Home and Out
2. Add two columns into tables Home and Out --> ID and Joint integer
3. Fill column ID in Home and Out table with RowID (row order) and Join column with constant for instance 1
4. Run following SQL statement
Select Home.ID, Out.ID, Distance(CentroidX(Home.obj), CentroidY(Home.obj), CentroidX(Out.obj), CentroidY(Out.obj), "m") from Home, Out where Home.Join=Out.Join order by Home.ID, Out.ID into Selection
or download CalcDist PRO from www.terris.sk - it is a trial version limited with number of the objects (100 objects). This program calculates distance between objects automatially.
Hope this help.
Best regards Stefan Majtan
Goal: I need to show the distance between each person's unique home address
and a specific unique addresses each person attends away from home (called
PL1)
Steps:
1) I geocoded and created centroids for two places 1) Home and Place1
respectively.
2) The geocoded and centroids for Home and Place1 were in separate tables,
so I queried them into one table (called Radom_hempstead_Home_PL1) by the
ID#s for each person from both tables.
3) I tried to run the following distance functions, but get no column with
the distance between the two places. I get a column of zeros. The centroids
between the HomeX, Home Y, Place1, Place1 are difference so the distance
should't be zero.
Here is the synax I used: _______________________________________ select columns: *From tables: Radom_hempstead_Home_PL1
Where condition is: distance ( XCoord_Home , YCoord_Home , XCoord_PL1, YCoord_PL1 , "ft")
into Table Named: selection ____________________________________________________________
I also tried "mi" which didn't work either.
Any suggestions
----- Original Message ----- From: "Woody Woodruff" <[EMAIL PROTECTED]> To: "Neil Evans" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Monday, February 02, 2004 8:47 AM Subject: RE: MI-L FW: Measuring distance between two points.
specifyDistance()function help: Distance( num_x , num_y , num_x2 , num_y2 , str ) Returns the distance between two locations. The first two parametersthe x and y value of the start location; the next two parameters specifythethex and y value of the end location; the str parameter is a distance unit name, such as "mi" or "km".
I use teh mnomoc Latty Fatty Y to rember which is which
Without writing an mbx, you will need lat and long (y and x) columns forobjects, use update with centroid(x) and agian for centroid(y).part
Depending on what 2 items you want to generte diatnces for, there are
different stratigies. If its distance to a set of objects from one object
(One store to many customers) use the actuall lat and long in the firstof the distance function and the fields Lattitude and Longitude for set ofand
points in a calculated query. I used teh Customer ID and the fields LATLONG for each customer location, and the known position of the store
(-84.82, 45.59) See below. the "Distance_To_Store" part is an alias to
label the column with, other wise the formula will be the Column heading.
some mapbasic text to show the steps
Alter Table "My_table" ( add Latitude Decimal(13,8) ) Alter Table "My_table" ( add Longitude Decimal(13,8) )
Update My_table Set Latitude = Centroid(y) Update My_table Set Longitude = Centroid(x)
Select ID, Distance(-84.82, 43.59,LONG,LAT,"mi") "Distance _To_Store" from
My_table into Selection
This generates a list of Customer IDs and the distance to the store from each customer Lat and Long.
William "Woody" Woodruff Zoning Administrator Charter Township of Union, Isabella County, Michigan -84.80947000 43.61095100 2010 S Lincoln Rd, Mt. Pleasant, MI 48858 (989) 772 4600 EXT 41 Visit our web site at http://www.geocities.com/ctuzoning/index.htm
-----Original Message----- From: Neil Evans [mailto:[EMAIL PROTECTED] Sent: February 03, 2004 07:15 To: [EMAIL PROTECTED] Subject: MI-L FW: Measuring distance between two points.
Simple peace, how do you measure distance between two points. Someone remind me what to do again.
Thanks for very much for your help
Neil
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