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0

I am not sure if this could be done in QGIS but you could use st_split for this if it helps. Try to make a buffer around your points and then split it where they intersect. A same question is asked at How to split a line at point positions?


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This does seem to be related an existing QGIS bug report http://hub.qgis.org/issues/4304 You could try using gdalinfo to find the list of supported formats like: gdalinfo --formats Which on this PC gives me: Supported Formats: VRT (rw+v): Virtual Raster GTiff (rw+vs): GeoTIFF NITF (rw+vs): National Imagery Transmission Format RPFTOC (rovs): ...


0

It seems something related to permissions kbuildsycoca4: ERROR creating database '/home/lyndon/.kde/cache-Gerhard-ThinkPad-W530/ksycoca4'! Insufficient permissions in target directory. Post the output of ls -l /home/lyndon/.kde/cache-Gerhard-ThinkPad-W530/ or try to give to all the .kde subtdirectories the appropiate permisions, probably read, write, ...


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Your question could have been more focused (try to write future questions such that they only have a single question). QGIS 2.x is Qt4, not Qt5. See Can I use QGIS with Qt5? Qt4 and Qt5 are not source compatible. SpatiaLite is developed using Linux and msys. It is possible to build it, but you can just download pre-built software from ...


0

I have been having the exact same problem ever since QGis left the 1.8 format. It seems like calls to set the active band from any multiband layer have been dropped. I have been asking about this for the pseudocolour plots for some time now, but no one seems to have an answer! Have you actually been able to set any layer as active and redraw that layer, ...


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The easiest way to do this at the moment is via the "lock layers for map item" check box in the map item's properties. This allows you to restrict which layers are visible in each map item. So, basically, you set up the map canvas how you'd like for one map, then check its lock layers check box. Then switch back to the canvas and set up the layers for the ...


1

the Global Administrative Districts has shapefiles for all countries.


1

Here is the data for Australia straight from their government's website: http://data.daff.gov.au/anrdl/metadata_files/pa_nsaasr9nnd_02211a04.xml Here is the data for New Zealand from their government's data portal: http://www.stats.govt.nz/browse_for_stats/people_and_communities/Geographic-areas/digital-boundary-files.aspx From here you can merge the two ...


0

I also needed to know how to rename bands in an open source environment so spent a whole day looking for answers. There is no way to name bands in QGIS while merging. But it can be done after the file is created, by editing their .aux.xml file. It works for both .tif and .img files, as far as I've researched. The solution is to include after each ...


0

Found a link which contained solutions to adding 2 layers or more: http://stackoverflow.com/questions/1769648/addition-with-null-values Basic gist is when using 2 columns: coalesce("Column_1"+"Column_2","Column_1","Column_2") Using 3 columns or more, I used: coalesce("Column_1",0.00) + coalesce("Column_2",0.00) + coalesce("Column_3",0.00) + ....... ...


2

Turns out it was just a case of quitting QGIS and reopening it again, thanks for the suggestions


0

You can use the Processing plugin which, once downloaded and installed, has the functions Merge Vector Layers or Join Attributes Table.


0

I guess your orijinal data is not in UTM. Becuse your file need to be in meters in such case. Utm is in meter originally you need to check your initial datum. When you transform to wgs84 it will still be in degrees.


3

You could try to use OpenStreetMap data. Global land and water polygons are freely available from http://openstreetmapdata.com/data/land-polygons, a service offered by Jochen Topf. In contrast to the above mentioned Natural Earth dataset OpenStreetMap data is much more detailed and therefore requires more disk space.


2

You might like to have a look at this document, which shows an example of using the Polygonizer to make a geological map. http://confound.me.uk/maps/ppv4.pdf‎ After some recent problems, in my version of QGIS (2.3.0-Master, from Ubuntugis) the Polygonizer is now working again. Search for 'Polygonize' in the Processing Toolbox. N.


2

There is the "Rectangles ovals digitizing” plugin in the official QGIS repository. To activate the tools in the tool bar you have to first select a vector layer containing polygon or multipolygon features. After that start editing on this layer. Of course, it doesn't work for vector layers containing point or linestring features.


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The Natural Earth website is pretty good for freely available Geographic data, inlcuding Country boundaries.


1

Try "STATEFIPS = 1 OR STATEFIPS = 12". Your current expression is effectively "(STATEFIPS = 1) or (12)", and since "12" will always evaluate to true this results in all features being selected.


0

Since your vector_selectbypoint class inherits from the UI class, get rid of: self.ui = Ui_vector_selectbypoint() You can then refer to the text browser using: self.txtFeedback The way your code is now, you are setting self.ui to your UI but never setting it up. That would require using: self.ui.setupUI(self) rather than self.setupUI(self)


1

You did not specify a file name for the export. In that case, QGIS tries to add ".shp" to a blank file name, which causes the error message you get.


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I'm editing this since I figured what the problem was. Sorry I put it as an answer but my first post was done as a guest and I don't know how to edit it. I installed QGIS through the windows installer and not through the OSGeo4W installer. it seems that with that installation I was missing something called libfreetype-6.dll I uninstalled and re installed ...


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Generally you can create a hyperlink to a folder on a web server by omitting a file from the path. So for example this is a link to the folder that contains GML schema: http://schemas.opengis.net/gml/ However, this isn't always possible because many web server administrators don't want users to root around in the file structure, so they either disable ...


0

It appears this was caused by some 'corrupt' spatial data. I cleaned up one of the files, and things all seem to work properly now.


0

Qgis has really made improvements in v2.2. I suggest using this version instead if you are interested in productivity.


0

These are the steps I followed to install Qgis 1.8 from source in my $HOME/qgis18 directory: Prerequisites: ccmake installed from synamptic; gdal,proj4,geos,etc. installed from Ubuntugis repository; Procedure: Download datasource from here $mkdir -p ${HOME}/qgis18 $cd qgis18 $mkdir build $cd build $ccmake .. (configure all paths and dependences) $make ...


1

You can snap a line to itself, but only after saving. My workaround is to digitize the line, but set the last point a bit offset to the first point, then save, and then move the last point to the first. As a consequnce, I start digitizing a new closed line with a point that is already created by another adjacent polygon if possible.


-1

Go to settings Go to snapping options Select river layer Select pixcel from dragdown menu Choose around 10 pixcel for snapping limit.


0

Here is an attempt to do this in R. I use gIntersect and compare the layer with itself. Every polygon intersects with itself, so I then use the row sums to determine if there is only one intersect and select those. library (rgeos) library(sp) # make some polys data (meuse) coordinates(meuse) <- ~x+y polys <- gBuffer(meuse, width=70, byid=T) ...


1

I am just playing around with this. I found the same site/formula that @Alex Tereshenkov mentioned in the comment above . Here is what my field calculator expression and codeblock look like: def CalcDate(JD): L= JD+68569 N= 4 * L /146097 L= L - (146097*N+3)/4 I= 4000*(L+1)/1461001 L= L-1461*I/4+31 J= 80*L/2447 K= L-2447*J/80 L= J/11 J= ...


3

I take no credit for the following Python snippet, which is taken from an ESRI idea found by Googling 'convert from julian to calendar date arcgis'. As trivia, they mention the data they were working with came from the FAA. There is also mention of data coming over from Excel in that format despite being entered differently. I apologize if my cut/paste ...


0

There are at least two formats with .grd/.gri extension. One is Golden Software grid - GDAL can easily handle it, so simply open it through Add Raster Layer, as Didier Blavet suggested. But there is also DIVA-GIS grid format. I found a maillist entry saying that only DIVA-GIS can open it. So you have basically two options: you can get and install DIVA, open ...


0

I suggest not to create such a matrix, which could be quite inefficient, but if you really need this, you create an ascii file with Long, lat, and value as columns, (which you can import in Matlab.) gdal_translate -of XYZ input.tif output.asc gdal is also available from qgis as a plugin (with a GUI), but you can use it directly as a command line. Note ...


1

I found the problem, the temperature RasterStack does not cover all the extent of the country I'm working on. I'm using E-OBS gridded dataset from European Climate Assessment & Dataset, by the way.


0

In PYQGIS a shape file can be save as a .csv with coordinates by: QgsVectorFileWriter.writeAsVectorFormat(vlayer, "xy.csv", "utf-8", None, "CSV", layerOptions ='GEOMETRY=AS_WKT') This is not working in QGIS 2.2 but will work again in QGIS 2.4.


1

The shapefile format has some limitations due to the underlying dbase database format. See: http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Geoprocessing%20considerations%20for%20shapefile%20output In your case, the limit of 10 characters field name and 255 fields total is hit. Try some other format, like spatialite. Or think about ...


1

The difference is only due to the symbology, your original raster is symbolized with a classified method and bilinear interpolation resampling. I don't know what's used to symbolize the second one, maybe just pixel values or classified with nearest neighbor resampling. You can manage this in ArcGIS using the Symbology and Display tabs of the layer ...


1

For GRASS you can use the r.colors to modify the color table for a raster map. r.colors also ships with pre-defined color maps for temperature scales. It's simple to use even r.colors map=spring color=celsius You can also copy the color table from one map to another r.colors map=spring2 raster=spring For more details see the GRASS GIS manual ...


0

Okay I figured it out. Make sure the coordinate reference system is the same for both the buffer layer as well as the census block layer. Select Vector > Data Management Tools > Join attributes by location. Set the "Target vector layer" to the buffer layer. Set the "Join vector layer" to the census blocks. Select the radio button for "Take summary of ...


0

I find that it sometimes gets confused if there are too many nodes on shared lines between features. Chack the geometry validity of the features too because geometry errors can cause problems. Also you could try adding features one by one and not trying to merge all of them together at the same time, if it isnt too time consuming


0

I could not find a way to do this in Grass, but it is possible in SAGA. Here is a brief recipe: 1) After you import the TIFF file into the project 2) you can go to the Properties panel in the Setting tab and lookk for Colors->Type->Scaling->Value Range You can see something like Value Range 5:15. 3) Click in the text box and replace those values with ...


0

You may use v.select in GRASS GIS with "operator=disjoint" - features do not spatially intersect. Note that it requires GRASS GIS been compiled with GEOS support. Just check if "disjoint" is a supported parameter in v.select. Edit: in case of one map only, check v.to.db and its parameter "sides". It extracts categories of areas on the left and right side of ...


0

In the GIS world, it is intended that all layers must have a Coordinate reference system (CRS). Without that, the application has no idea how to put various data sources together. Usually, Raster images have a CRS stored inside. If not, you have to georeference it using known points inside the raster and coordinates form another source. A common way is to ...


0

It would be better if you ask the user password. You can assign a variable and get the value of the variable from user with a dialog. refer to the link please How to connect a PyQGIS plugin with Postgres?


0

Merge tool will merge other polygon to selected polygon. So if want to merge all other polygon to single polygon then select and merge.


1

Yes: 1) The proposed solution (Using processing algorithms from the console) import processing # find the algorithm processing.alglist("Multipart to singleparts") Multipart to singleparts----------------------------->qgis:multiparttosingleparts # help processing.alghelp("qgis:multiparttosingleparts") ALGORITHM: Multipart to singleparts ...


1

Take a look at ArchaeoFusion from the Center for Advanced Spatial Technologies. It appears to handle magnetic survey data. Free as of now, and has been for quite some time.


11

create a new field and copy the first two digits from the left using the field calculator -> for text, you can use (left(fieldname,2)) in the field calculator. With numeric field you can use floor(fieldname/1000) dissolve your polygons based on this new field -> this command is in vector -> geometry -> dissolve


1

This is a really good feature idea - thanks for the inspiration. I've just added this ability to QGIS. So if you run a current snapshot, or when 2.4 is released, there's an easy way to set a filter for an attribute table:


0

Here is another workflow, using ogr2ogr with GCP points: Extract the lines as svg (as above) load into inkscape and save as dxf Load into QGIS, with EPSG:31467 as CRS Read a couple of coordinates from significant edges of the surrounding city border Open OSM editor JOSM and download the relation 62591 of the city border Save that as GPX Load the border ...


0

If the selected features and your created layer both share an identical column in their attributes tables. (ie maybe under ID they are both called FT001) then you can do a join and this will add additional attribute details from your selected feature layer. This is also handy if you want to just add a .csv folder and equipe a shapefile with the csv data. Is ...



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