MapInfo Pro

Hello MI,

I have a need to convert a line objects table (of protected shop frontages) to polygons. I need just 3 metre buffers.

I've used the Buffer>Buffer Objects function to create a 3 metre buffer for each map object. This works well and carries over the object attributes from the line to the new buffer polygon.

However, the resulting table still contains the original line objects sitting within the buffer polygons. How do I remove the lines leaving just the polygons?

Thanks,
Stuart

------------------------------
Stuart Carter
Corporate GIS Manager
Southwark Council
London
------------------------------

Hi Stuart,

You can select the lines from your table using the following query:

Select * from YourTable where str$(obj) in ("line","polyline") into lines

Then delete the lines.  I would also pack the table.

If you use Buffer --> Buffer Table instead of Buffer Objects, you can create the buffer polygons into a new table.

------------------------------
James Nolet
Dooley Mitchell & Morrison Pty Ltd
Mentone, VIC, Australia
------------------------------

Original Message:
Sent: 03-10-2020 12:52
From: Stuart Carter
Subject: Delete original line features from resulting buffer table

Hello MI,

I have a need to convert a line objects table (of protected shop frontages) to polygons. I need just 3 metre buffers.

I've used the Buffer>Buffer Objects function to create a 3 metre buffer for each map object. This works well and carries over the object attributes from the line to the new buffer polygon.

However, the resulting table still contains the original line objects sitting within the buffer polygons. How do I remove the lines leaving just the polygons?

Thanks,
Stuart

------------------------------
Stuart Carter
Corporate GIS Manager
Southwark Council
London
------------------------------

Original Message------

Hi Stuart,

You can select the lines from your table using the following query:

Select * from YourTable where str$(obj) in ("line","polyline") into lines

Then delete the lines.  I would also pack the table.

If you use Buffer --> Buffer Table instead of Buffer Objects, you can create the buffer polygons into a new table.

------------------------------
James Nolet
Dooley Mitchell & Morrison Pty Ltd
Mentone, VIC, Australia
------------------------------

Stuart,

Two tips on how to avoid adding objects to the table:

1. Use Buffer Table

As @James Nolet said, use the Buffer Table command. This will ask you to select the output table where you can create a new table based on the structure of the input table.

2. Update the existing records with the (Cartesian)Buffer() function

You can also use the MapBasic Window, or the new v2019 SQL Window, to update the existing records with a new spatial object. Before doing so, you might want to create a copy of your input table.

I have used the CartesianBuffer function assuming that your data is based on the British National Grid coordinate system. If it's based on a Longitude/Latitude projection, use the Buffer() function.

Update Addresses
   Set OBJ = CartesianBuffer(obj, 24, 3, "m")

​

------------------------------
Peter Horsbøll Møller
Distinguished Engineer
Pitney Bowes Software & Data
------------------------------

Original Message:
Sent: 03-10-2020 12:52
From: Stuart Carter
Subject: Delete original line features from resulting buffer table

Hello MI,

I have a need to convert a line objects table (of protected shop frontages) to polygons. I need just 3 metre buffers.

I've used the Buffer>Buffer Objects function to create a 3 metre buffer for each map object. This works well and carries over the object attributes from the line to the new buffer polygon.

However, the resulting table still contains the original line objects sitting within the buffer polygons. How do I remove the lines leaving just the polygons?

Thanks,
Stuart

------------------------------
Stuart Carter
Corporate GIS Manager
Southwark Council
London
------------------------------