3,725 reputation
1414
bio website confound.me.uk
location Caversham, Reading, England
age 72
visits member for 2 years, 8 months
seen 8 hours ago

Nick Hopton is a retired ancient person who's background is in quarrying and ready-mixed concrete. His ambitions include learning more about how to make good maps and becoming an actuarial nightmare for his pension fund.


16h
comment How to go with…somewhat complex geological maps in QGIS?
I noticed a thread on the QGIS User list the other day about 'Polygonize' and OS X. osgeo-org.1560.x6.nabble.com/… Not something I know about I'm afraid.
16h
comment How to go with…somewhat complex geological maps in QGIS?
Until lately I was getting messages similar to yours with 'Polygonize', I think this was something to do with the version of Shapely installed on my system. But the problem has disappeared in recent upgrades. Pleased to hear that it's working for you too. N.
17h
comment How to go with…somewhat complex geological maps in QGIS?
Would you check the Polygonizer using this shapefile? dl.dropboxusercontent.com/u/45121071/laxlines.zip
18h
answered How to go with…somewhat complex geological maps in QGIS?
Apr
11
comment How to apply a specific Rendering to an Image and export to JPEG?
Does this work for you? It was the first thing I tried but but the output image was either all red or all green depending on the ordering of the items in the text file.
Apr
4
revised How to generate Non-smooth/crude Contour Lines in QGIS?
added 124 characters in body
Apr
4
answered How to generate Non-smooth/crude Contour Lines in QGIS?
Mar
19
comment Is there a good qml or sld file available for QGIS + Openstreetmap data?
There was an interesting thread on this topic on the Developer list that included links to QML files. See osgeo-org.1560.x6.nabble.com/Styling-OSM-data-td5102503.html
Mar
13
comment gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale
It uses pixel values, the raster polygonizer makes polygons that enclose groups of pixels of the same value. This is why it is sometimes important to sieve out small clumps of pixels before running the polygonizer or you can end up with huge number of tiny polygons. Which I think is what you have.
Mar
9
revised gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale
added some text
Mar
9
answered gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale
Mar
7
comment How can I locate additional GCPs?
Okay, it's an exercise. You could have a look at the area in Google Earth and see if it's possible to match four features on the imagery with four features on your map and note the GE coordinates for them. Obviously I don't know what CRS you are using but you can set GE to show UTM coordinates if required.
Mar
6
comment How can I locate additional GCPs?
Why do you need so many GCPs? Is the scan badly distorted?
Mar
5
comment Eastings/Northings OSGB36 Grid origin
For batch converting OS grid references to OS coordinates (and the other way) I find NG Converter very useful. digimap.edina.ac.uk/webhelp/os/data_information/os_data_issues/…
Mar
5
answered Line bearing for wind direction for plume of smoke QGIS
Mar
2
comment Loading OSM data into QGIS
What I would do is draw a polygon in Google Earth, a rectangle say, with extents of say 20 km x 20 km. Save this a KML file (not KMZ) and load it into QGIS. This will set some reasonable extents. Then try loading your OSM data (don't bother about databases at this stage).
Feb
28
answered Loading OSM data into QGIS
Feb
19
comment How do I use SQL in the field calculator to populate a new column?
This was the solution I used, but thanks to all.
Feb
19
accepted How do I use SQL in the field calculator to populate a new column?
Feb
18
asked How do I use SQL in the field calculator to populate a new column?