RE: MI creating points from centroids
Hi Sidney It's pretty simple actually - just a few steps. 1) Make a copy of your original table - use File | Save Copy As 2) Close the original and open the copy 3) Use the Table | Maintenance | Table Structure command to add two columns to your new table - call them X and Y and set the type to Decimal 16, 8 4) Use the Table | Update Column command to get the centroid information into the new columns - you'l do this twice, once for X and once for Y. Pick your table, select the X or Y column and then, for the Value field, type either CentroidX(obj) or CentroidY(obj). 5) Save your table 6) Select Table | Maintenance | Table Structure and select your table. Uncheck the "Table Is Mappable" option and click "Ok". You have just removed the map objects from your table. 7) Select Table | Create Points, select your table, make sure the X and Y columns are set correctly, and click Ok. You now have a map of points representing the centroids of the polygons you started with. Regards, James James L Marlow Director, Geographic Information Systems Channel Marketing Corporation 15032 Beltway Drive Addison, Texas 75001 Telephone 1 (972) 858-9600 extension 331 Facsimile 1 (972) 858-9601 email: [EMAIL PROTECTED] www: http://cmcus.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Thursday, April 27, 2000 2:48 PM To: [EMAIL PROTECTED] Subject: MI creating points from centroids Hello users, I have a polygon coverage of Census Enumeration Areas for a particular urban region, from which I would like to create a point theme consisting solely of points located at the centroids of each Enumeration Area. Has anyone done something like this before, and if so, how do you go about doing it? Any help would really be appreciated. Regards, -Sidney - - Sidney McLean Income Security and Social Development Studies Applied Research Branch Human Resource Development Canada 165 Hotel de Ville Phase II, 7th Floor Hull, Quebec K1A 0J2 -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
RE: MI creating points from centroids
Try this, Add a column called LAT and one called LONG to your table under tablemaintenancetable structure (set them to type of float). Update the LAT column with Centroid(y), and the LONG column with centroid(x). Export a copy of that table as delimited text. Open the text file, and create points using LAT and LONG, and voila, you have a point layer of the centroids of those polygons complete with the table of attributes. Will Mitchell GIS Manager The Environmental Company, Inc. 2496 Old Ivy Rd Charlottesville, VA 22905 ph 804.295.4446 fx 804.295.4435 http://www.tecinc.com -Original Message- From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]] Sent: Thursday, April 27, 2000 3:48 PM To: [EMAIL PROTECTED] Subject: MI creating points from centroids Hello users, I have a polygon coverage of Census Enumeration Areas for a particular urban region, from which I would like to create a point theme consisting solely of points located at the centroids of each Enumeration Area. Has anyone done something like this before, and if so, how do you go about doing it? Any help would really be appreciated. Regards, -Sidney - - Sidney McLean Income Security and Social Development Studies Applied Research Branch Human Resource Development Canada 165 Hotel de Ville Phase II, 7th Floor Hull, Quebec K1A 0J2 -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
RE: MI creating points from centroids
Sidney Another alternative to Will's suggestion is to make a copy of the table (called say "My_New_Table") and issue the following command in the mapbasic window Update My_New_Table set object = createpoint(centroidx(obj),centroidy(obj)) This bypasses the need to store the x/y (lat/Long) values regards Martin == Martin Roundill GIS Manager Waitakere City Council Private Bag 93109 Henderson Waitakere City New Zealand -Original Message- From: Mitchell, Will [mailto:[EMAIL PROTECTED]] Sent: Friday, 28 April 2000 09:02 To: '[EMAIL PROTECTED]'; [EMAIL PROTECTED] Subject: RE: MI creating points from centroids Try this, Add a column called LAT and one called LONG to your table under tablemaintenancetable structure (set them to type of float). Update the LAT column with Centroid(y), and the LONG column with centroid(x). Export a copy of that table as delimited text. Open the text file, and create points using LAT and LONG, and voila, you have a point layer of the centroids of those polygons complete with the table of attributes. Will Mitchell GIS Manager The Environmental Company, Inc. 2496 Old Ivy Rd Charlottesville, VA 22905 ph 804.295.4446 fx 804.295.4435 http://www.tecinc.com -Original Message- From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]] Sent: Thursday, April 27, 2000 3:48 PM To: [EMAIL PROTECTED] Subject: MI creating points from centroids Hello users, I have a polygon coverage of Census Enumeration Areas for a particular urban region, from which I would like to create a point theme consisting solely of points located at the centroids of each Enumeration Area. Has anyone done something like this before, and if so, how do you go about doing it? Any help would really be appreciated. Regards, -Sidney - - Sidney McLean Income Security and Social Development Studies Applied Research Branch Human Resource Development Canada 165 Hotel de Ville Phase II, 7th Floor Hull, Quebec K1A 0J2 -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
RE: MI creating points from centroids
Sidney, This is a one step process using the MapBasic Window: 1. First make a copy of your table 2. Open the MapBasic window (Options Show Mapbasic Window) 3. Type in: update YOUR_TABLE set obj=CreatePoint(CentroidX(obj),CentroidY(obj)) where YOUR_TABLE is the name of your mapinfo table. Hope this helps, Chris Perry Systems Development CoOrdinator Parks Victoria Melbourne, Australia Ph: 61 3 9816 6800 Fax: 61 3 9816 9876 [EMAIL PROTECTED] -Original Message- From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]] Sent: Thursday, April 27, 2000 3:48 PM To: [EMAIL PROTECTED] Subject: MI creating points from centroids Hello users, I have a polygon coverage of Census Enumeration Areas for a particular urban region, from which I would like to create a point theme consisting solely of points located at the centroids of each Enumeration Area. Has anyone done something like this before, and if so, how do you go about doing it? Any help would really be appreciated. Regards, -Sidney - - Sidney McLean Income Security and Social Development Studies Applied Research Branch Human Resource Development Canada 165 Hotel de Ville Phase II, 7th Floor Hull, Quebec K1A 0J2 -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
