Create rings around multiple points

[K2J]

I'm hoping that someone can help me with this.  I had in the past used MapInfo, but this was about 10 years ago.  At that time, there was a way to create individual rings around each point in a table.  From there I was able to get data on items within those circles by running a query. I've decided to start using MapInfo again and have purchased 12.0.  However, it appears that I can no longer create these circles unless I draw them one at a time on the map.  Please tell me there is a way to create individual rings for an entire table.  I have 50-60 points that need 5 mile rings around them.  I really don't want to have to draw 50-60 rings myself.

Thanks.

K2J

[Tony Pilkington]

Load and display a copy of your table

Make it editable

set the colouring you want to use  by setting the region style

 

Use options –>  show mapbasic window

in the window type the following:

 

set coordsys window frontwindow()

set distance units “mi”

Update   table  Set  obj =  createcircle(centroidx(obj),centroidy(obj),6)

 

save the table

--
--
You received this message because you are subscribed to the
Google Groups "MapInfo-L" group.To post a message to this group, send
email to mapi...@googlegroups.com
To unsubscribe from this group, go to:
http://groups.google.com/group/mapinfo-l/subscribe?hl=en
For more options, information and links to MapInfo resources (searching
archives, feature requests, to visit our Wiki, visit the Welcome page at
http://groups.google.com/group/mapinfo-l?hl=en

---
You received this message because you are subscribed to the Google Groups "MapInfo-L" group.
To unsubscribe from this group and stop receiving emails from it, send an email to mapinfo-l+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4765 / Virus Database: 4015/8147 - Release Date: 09/03/14

[Ross Nixon]

Good solution from Tony. Makes much smoother circles/ellipses than what I've been doing.

My practice is/was to buffer the points, specifying a high number of segments to make the region look like a circle.

Ross

[Peter Horsbøll Møller]

I would recommend using buffers instead of Circles.

Buffers are more "precise" as they have nodes all the way round in the perimeter.

A circle is defined by it's corner cordinates.

I'm assuming that the goal here is to be able to select all points within a given distance from another point.

If that's the case, buffer should be your choice

Peter Horsbøll Møller

Pitney Bowes Software

---

From: a.j.pil...@talk21.com
To: mapi...@googlegroups.com
Subject: Re: [MI-L] Create rings around multiple points
Date: Wed, 3 Sep 2014 22:27:54 +0100

[Tony Pilkington]

True, a buffer is limited to 100 nodes. A circle to 1,048,570 (max, default to 100) by using the set resolution statement before issuing a converttoregion statement.

If you set it to 361, then you can read out direction, once you know which node is North.

[Peter Horsbøll Møller]

Tony

I had completely forgotten about the Set Resolution statement which of course is a great way to add extra nodes to your region.

So your statement should actually be changed to this:

set coordsys window frontwindow()

set distance units “mi”

Set Resolution 361

Update table Set obj =  ConvertToRegion(createcircle(centroidx(obj),centroidy(obj),6))

Mine would look like this to achieve the same result:

set coordsys window frontwindow()

Update table Set obj =  Buffer(obj, 361, 6, "mi")

BTW, the maximum resolution for buffers these days is 500 - but even that is still far lower than the 1,048,570 that can be set via the Set Resolution statement. Not sure how often you would use that high resolution though.

Peter Horsbøll Møller

Pitney Bowes Software

---

From: a.j.pil...@talk21.com
To: mapi...@googlegroups.com
Subject: Re: [MI-L] Create rings around multiple points

Date: Thu, 4 Sep 2014 07:21:35 +0100

[Thomas Bacon]

“If you set it to 361, then you can read out direction, once you know which node is North.”

 

That is particularly clever, I like it!

 

Tom Bacon

GIS Engineer, Mouchel

T 01444 472380 │ E thomas...@mouchel.com │ W www.mouchel.com

Our values: innovation │ excellence │ integrity │ responsibility

Mouchel Limited (Mouchel) is registered in England and Wales with registered number 01686040 at Export House, Cawsey Way, Woking, Surrey, UK, GU21 6QX.  The information in this e-mail is confidential and may be legally privileged. It is intended solely for the addressee. Access to this email by anyone else is unauthorised. Any views or opinions expressed in this e-mail may be solely those of the author and are not necessarily those of Mouchel. No contracts may be concluded on behalf of Mouchel by means of email communications. Mouchel reserves the right to monitor and intercept emails sent and received on our network.

[Tony Pilkington]

On the other hand:

node_limit  is a SmallInt value between 2 and 1,048,570 (inclusive); default is 100.

1048570 is somewhat larger than 65536

 

http://www.bl.uk/onlinegallery/features/lieland/m3-3-1.html is a good test of contouring