RE: MI-L Joined thematic gridDear List Thanks to all those who replied with solutions to my "Grid Hot Spot" problem.
I have now managed to solve the problem with the help of a GIS consultant on the list (Sheila Quan). First I used SQL to select a particular type of habitat and then I used the Thematic Mapping Range Template. Once selected I then selected the 1 km grid table and joined it to the SQL selected habitat (query1) and calculated the count. This gave me exactly the map I needed. I now have to work out how to save this map as I need to convert it to shape file format. I am also working on some of the other options that people sent me (just for interest really) but I am not having much joy with using straight SQL queries (never my strength for the more complex workings). Another problem I have is how to amalgamate various types of habitat codes in one column into new common codes in another column. For example I have codes A111, A112, A131, and A132 (amongst many other codes for other habitats) in one column and I want to convert these into W (for woodland) in another column and so on until I have done all the code amalgamations. I have made the new column and tried various types of update but to no avail. This I am sure is simple but I am as usual finding it tricky to find the correct instructions for this specific problem - undoubtedly something to do with update column. Hoping there is someone out there who knows the answer to this. Thanks in advance Jacqui Middleton ----- Original Message ----- From: Driver, Greg 9434 To: 'Jacqui Middleton' Sent: Wednesday, July 13, 2005 4:03 PM Subject: RE: MI-L Joined thematic grid Jacqui, Is the Map Plot grid a raster layer? If it is, then you will have to use Vertical Mapper (VM) as MapInfo has limited analysis functions for raster layers. I'm not that familiar with VM (other than using it for height data) but it does have raster grid analysis functions. Just looking at the help file it looks like you could possible use the Region Inspection function or the Polygon Overlay function to update a coincident grid layer (your 1km sq grid). Once you've analysis/updated the grid you could then create contours using the Contour option in the Grid Manager. If your Map Plot grid is a vector layer than you could do some SQL to select attributes using some spatial function (within or contains etc) that are coincident between the two grid layers. You could then create a raster grid from this data using VM and create contours from this grid layer. You may well be better off converting the vector layers into raster grids and using VM to do the analysis/ HTH Greg. -----Original Message----- From: Jacqui Middleton [mailto:[EMAIL PROTECTED] Sent: 13 July 2005 15:11 To: MapInfo-L Subject: MI-L Joined thematic grid Dear List I am trying to find hot spots (i.e. the best places) for particular habitats across a UK county. I have a Map Plot grid of various habitats (100 ha sq) and another empty grid of 1 km sq. The only information I am interested in is the presence or absence of any particular habitat in the smaller grid squares and finding out how many occur per 1 km square. I am hoping to produce a series of maps of the 1km squares across the county that have the most (and least) of any particular habitat. The map should end up looking a bit like a contour map with a legend to indicate each of the habitat hot spots. I have looked at the help file on thematic maps and it appears that this must be the way forward. I have tried a few options using the help file on thematic maps (and the guide "Inside MapInfo") but have not got anywhere. Any helpful hints and/or instructions would be welcome ... If MapInfo (V6.5) can not do what I hope to achieve could Vertical Mapper (V2.6)? I have only used proper height data with VM so am puzzled as to how I could use it to map presence/absence data. Thanks in advance for any help and I will of course acknowledge any instructions that have helped me achieve my aims! All the best Jacqui Middleton Internet communications are not secure and therefore Surrey Police does not accept legal responsibility for the contents of this message. This email and any attachments may be confidential. They may contain privileged information and are intended for the named addressee (s) only. They must not be distributed without our consent. If you are not the intended recipient, please notify us immediately and delete the message and any attachments from your computer, do not disclose, distribute, or retain this email or any part of it. Unless expressly stated, opinions in this email are those of the individual sender, and not of Surrey Police. We believe but do not warrant that this e-mail and any attachments are virus free. You must therefore take full responsibility for virus checking. Surrey Police reserves the right to monitor all email communications through their networks.
