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1

In this case, you need to know exact CRS your XY data represents. For that use reference data such as imaginery, aereal photography and compare XY data with known locations. For this you can use pluggin coordinates capture is useful. Please refer when using Datum transformations to parameters values, as @Gerardo Jimenez pointed out: ...


0

other than tile size, as noted by lrssvt, you can also set some timeout and tile retry parameters Default timeout per connection is in Settings->Options->network->Timeout for network requests Retry in case of timeout is in Settings->Options->network->Max retry in case of tile request errors I coded the last retry parameters in qgis, funded by Regione ...


0

The CRS layer that you loaded in QGIS is WGS84 (geographic system) and you are setting a grid interval in meters, try to enable 'on the fly' CRS transformation and setting a proper projected CRS (i.e EPSG:32633). Take a look at Project properties dialog to do it:


1

Sometime that could occurs with slow connection. You could try to set a tile size for your WMS layer. Change Tile size (e.g 256x256) in WMS Connecition dialog and you see if it works for you: Sometime it helped me for large compositions. Hope this helps.


2

I use GPX format to transfer data from and to Basecamp. The older version I use can also export csv, and import kml and csv. But since I use GPX for export to and from the GPS unit too, I prefer that format for all exchange. You can however not use the Garmin based .img files inside QGIS.


2

I finally managed to fix it on my own, thx anyway ;) The trick is to leave interval units as is: Maps units.


0

If the Reference System for the shape is equal, you can use "intersect" tool (vector>geoprocessing tools>intersect). The vector result have, in the attribute table, the values of two vector that you have processed (wetland areas and boundary).


0

Seems like the settings are not stored correctly. Here's the bug report for future reference http://hub.qgis.org/issues/11713


0

Ok, I found where was the problem. Of course, you have to specify which kind of protocol to use, so the correct syntax was: protocol: new OpenLayers.Protocol.HTTP({...})


0

Found what was the problem. Following that example, I thought that that syntax was referring to properties inside OpenLayers. Instead it wasn't. Where you have to indicate the style, you have to put the name of the namedLayer of your sld, like so: var format = new OpenLayers.Format.SLD(); OpenLayers.Request.GET({ url: 'style/roadsStyle.xml', ...


0

THe short answer is: I can;t see a way. However, changing attributes on a feature is time consuming at times (I have have a hard time figuring out why it happens). Thus, this should speed up your code a bit: pr.addAttributes( [QgsField(aName, QVariant.Double) ] ) attrs={} #------ # Add Values to Triangle Features in Values ...


1

In GRASS GIS, you can use r.thin for this task: The code implements the thinning algorithm described in "Analysis of Thinning Algorithms Using Mathematical Morphology" by Ben-Kwei Jang and Ronlad T. Chin in Transactions on Pattern Analysis and Machine Intelligence, vol. 12, No. 6, June 1990, along with further subsequent improvements. In QGIS, you can ...


0

In the end that's what I did - ripped some code out. Got the coordinates that I needed and then had to play around with the json job done. I got the javascript from here. http://blog.sallarp.com/geojson-google-maps-editor.html


0

With ArcGIS Spatial analyst, you can use the "thin" tool. Their algorithm is described in Zhan, Cixiang, 1993, A Hybrid Line Thinning Approach, Proceedings Auto-Carto 11, Minneapolis , pp. 396-405 As a remark, if you are interested in the process, you can also have a look at the skeletonization process in mathematical morphology. I don't know about a ...


0

Please consider to use v.net.path - finds shortest path on vector network or v.net.alloc - allocates subnets for nearest centers. See also the list of available vector network algorithms. The v.distance command will find the shortest direct distance but you likely want to follow the network in order to obtain more realistic distances.


0

I would suggest taking a look at the ArcScan toolbar if you are using ArcGIS. It has a range of functions in addition to Raster vectorisation which I think should help. Specifically the Raster Cleanup tools such as erosion and dilation which will make your lines thinner. Also check out raster snapping as that may also be useful. The image below is from the ...


4

You can multiply the value by 100 in the column definition and then add the % signs in the legend format as shown here:


0

loaded plugins and their instance are available in the dict qgis.utils.plugins you can manage load and unload with other methods in qgis.utils (do help(qgis.utils) in pythonconsole to show static methods available) this is only the base to solve you problem, you should manage check if running or not using some method in your plugin, or you can check if ...


1

similar to .area(), you can use .length() . For a polygon it yields the perimeter. perimeter=feature.geometry().length()


0

There were some issues with QGIS 2.6 crashing with old projects and the print composer: http://hub.qgis.org/issues/10756 https://hub.qgis.org/issues/11685 You can try the latest dev build, which has some bugs fixed, or wait until a bugfix release 2.6.1 is released. Creating a new project from scratch should be save.


0

The solution for my problem was the Nearest Neighbor Join Plugin.


1

You might have installed the TileMapScaleLevels plugin which forces the use of scales fitting to Google or Openstreetmap tiles. Either deinstall the plugin, or deactivate the scaling inside the plugin.


2

The shapefile you provided seems to be valid, and the projection in the prj files states (if im not mistaken) that your coordinates of each vertex are tied to WGS84 (EPSG:4326) Using ogr2ogr PGDump driver you can translate your shapefile to a sql querry that can be used to insert data into the database: If you are in Windows you can open the console with ...


0

The CRS data you report looks rather broken, with the k factor value stored in other parameters where it does not belong. For reprojecting rasters, you have to use Raster-> Projections -> Warp. Reprojection using Save As only works for vector data.


2

3D is not (yet) implemented in QGIS, but you can store the height in an attribute table field and create a 3D output manually with ogr2ogr -z_field fieldname outside QGIS. See Is it possible to create 3D dxf with OGR? for an example. This is rather 2.5D, because all vertices of a line must have the same elevation (as contours have). In QGIS, you could use ...


1

This is a bit of a late answer, but I thought it was worth contributing. As a polyline is just a series of points you should be able to obtain the Mean value you want by converting the Polyline nodes into points by going Vector > Geometry Tools > Extract Nodes... You can then extract the underlying Raster values for each of these points by using the Point ...


0

You can use Explode Lines in the Processing toolbox to turn each segment into an individual line. Have a look here: Simple automated way to split all lines in layer at vertices using QGIS? You can then open the attribute table of the layer with the newly split lines and use the field calculator to calculate the length into a new attribute with the... ...


0

In QGIS, it works only when both layers share the same CRS. If you switch On-the-fly-reprojection OFF, they should still align. If not, save one of the layers to another name and the CRS of the other, add that to the canvas, delete the first layer, and the intersection will work.


5

First case: insert new polyline You have to define the Polyline like so: pLine = [QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,2)] it is a list-of-QgsPoint. After you can put more QgsPoint into the list by append to insert the element at the end of the list: pLine.append(QgsPoint(3,2)) or inserting some vertex point at a specific location of the list: ...


0

I'm not sure but maybe you have to disconnect the signal layersWillBeRemoved from the default slot removeMapLayers.


1

You have to build the proj.4 string for the CRS from the parameters given: +proj=lcc +lat_1=44.883333 +lat_2=45.133333 +lat_0=44.791111 +lon_0=-93.383333 +x_0=152400.000000 +y_0=30480.000000 +a=6378418.9409999996 +b=6357033.3098455509 +towgs84=0,0,0,0,0,0,0 +units=us-ft +no_defs Note that x_0 and y_0 have to be in meters, while false Easting and Northing ...


1

There is something wrong with the Shell where it does not load the Grass /bin into $PATH My solution is to do it manually inside the Shell. $ echo $PATH /usr/bin:/bin:/usr/sbin:/sbin $ PATH="/Applications/QGIS.app/Contents/MacOS/grass/bin:$PATH" $ export PATH $ echo $PATH /Applications/QGIS.app/Contents/MacOS/grass/bin:/usr/bin:/bin:/usr/sbin:/sbin ...


1

https://rbcgis.wordpress.com/2014/11/19/qgis-svg-fill/ Thanks again for the help everyone, I made a tutorial to show how I did it.


2

You could: Generate contours at the desired intervals from your DEM and use the lines to cut up your polygon. Clip your DEM using your polygon, then reclassify the DEM using the desired interval ranges, followed by a little math - get the number of pixels in each class times the area of a pixel. (See Measuring area of raster classes? which discusses ArcGIS ...


0

Finally I found this thread, which answers the question for my needs: "The "no_defs" item ensures that no defaults are read from the defaults files. Sometimes they cause suprising problems." http://lists.osgeo.org/pipermail/mapserver-users/2003-November/046863.html


1

QGIS is not designed to handle J2000 data. Your data would have 4 coordinates (X,Y,Z and time), while QGIS only handles 2-dimensional coordinates (long and lat or X and Y). It is possible to reproject coordinates with cs2cs if you set the prime meridian according to the time. Every hour from 12 UTC is a shift of 15° to the greenwich meridian: put 7 51 in a ...


1

The EPSG registry lists two versions of CGCS2000: EPSG:4479 uses a 3-dimensional cartesian coordinate system based on the Earth's center EPSG:4480 uses Latitude, Longitude and ellipsoidal height. For the first one, see Help defining custom CRS in QGIS 2.2 how to use it in QGIS and the limitations of that CRS. For the second one, you can use the projection ...


1

Currently you can't edit a Shapefile layer while it is filtered. However, if you add a database layer, you can edit the layer while a filter is applied. This works with SpatiaLite and PostGIS, and I assume that it also works with Oracle and MSSQL connections. If this is the main functionality you need, though, SpatiaLite is easiest to work with as it is a ...


-1

I have added centroids to every polygon and this made the image a lot nicer from my point of view. thanks to Chris W


2

If you are using version 2.6 you can use a grid in a different CRS from the layers and project. You can even have more than one grid. The only thing for if you want a graticule is to set the X and Y spacing in decimal format. As you can see in the image I set the X and Y spacing to show lines every 15 minutes. Also you can see in the image that you can ...


0

thanks for the answers. The problem was that I had to set both 'resp' and 'rast1' variables to None after each iteration in the for loop, so my code end up like this entries = [] rasters = os.listdir("C://test/Rasters/") for i in range(0, len(rasters)): raster = "C://test/Rasters/"+rasters[i] resp = QgsRasterLayer(raster) rast1 = ...


1

I had the same problem. This should solve the bug (QGIS 2.6 under Windows): close QGIS using regedit.exe, search for "Plugin-GeoReferencer". This should point to a folder under \HKEY_CURRENT_USER\Software\QGIS\QGIS2\Plugins (optional: export a .reg version of the fodler for back-up) delete the folder "Plugin-Georeferencer" restart QGIS. Georeferencer ...


0

The issue is likely that 'resp' goes out of scope and is deleted when the for loop ends. Then when you try to use it in the calc = QgsRasterCalculator... line QGIS crashes. Try initializing 'resp' outside of your loop first. Something like: ... resp = None for i in range(0, len(rasters)): ... should do it.


1

The line breaks are in Classic Mac (CR); they should be in Unix (LF). I fixed this by opening my file in TextWrangler and changing the line encoding in the save as screen.


1

I do not believe this works in Version 2.6 having played with this for 3 hours and no joy. If it is an implementation, it is far from intuitive. Can we have a link to an updated and correct tutorial?


1

There's a more recent plugin available now called AutoTrace: https://plugins.qgis.org/plugins/autoTrace/ Some decent instructions are here: http://www.lutraconsulting.co.uk/products/autotrace/ It's been a while since I did digitizing in Arc, but I found the AutoTrace plugin to be at least as easy as my memories of the ESRI version.


1

According to spatialreference.org, CGCS2000 should be +proj=longlat +ellps=GRS80 +no_defs The usual approach is to add this definition as a custom CRS if you cannot find it in the default CRS list of QGIS.


0

Yes, there is a tool in QGIS for creating heatmaps. It should be pre-installed (see screenshot below): This link gives a detailed step by step guide on using the tool: http://www.qgistutorials.com/en/docs/creating_heatmaps.html Also refer to: How to adjust the granularity of a heat map in QGIS? How to create heatmap (concentration of points) in QGIS?


0

The problem is that the WFS provider of QGIS appends BBOX element to the main URL for unchached features request and if a filter exists it produces: msWFSGetFeature(): WFS server error. BBOX parameter and FILTER parameter are mutually exclusive in GetFeature. So to solve the problem the BBOX element should be included in the FILTER element to get a request ...


0

I've been trying against a Geoserver / Windows server 2003 installation, and it works. Doesn't work when it's a Geoserver / Centos Installation. With Udig WFS-T updates against a Geoserver / Centos are commited. Please also refer to: QGIS WFS Error - Could not commit changes to layer



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