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3

Finally, that is a very easy treatment with the MMQGIS plugin (Quantum GIS Plugin Repository). It allows to rewrite on another table using selected column and chosen order. It also works for the circles problem


3

drag-drop an Excel XLSX file onto the layer widget double click tool QGIS geoalgorithms\Vector creation tools\Point layer from Table, choose the new layer as Input layer and specify the columns representing X- and Y-field, run the process Two steps using current QGIS versions.


2

If your goal is to create a polygon representing the outline of a set of features, you're probably looking to create the concave-hull of this features set. While the creation of a convex-hull is a pretty straightforward operation, because there is only one possible convex-hull for a given set, this is not true in the case of the concave-hull. Because ...


2

Here’s my solution. I gave up with ArcGIS and QGIS, instead opting to output the data to file and perform the calculation in R. # Load library library(raster) # Load chlorophyll data chloro <- raster("../data/chloro.tif") # Load polygons poly <- shapefile("../data/poly.shp") # Extract data in polygons poly.chloro <- extract(chloro, poly) # ...


2

Tweepy is a python module, like any other module you must install it to the Python instance you wish to use. To use it within the plugin you must install it to your Qgis Python instance (located in your OSGeo4W folder on windows). For instructions on installing into Qgis's python you can see this guide.


2

This answer comes with a hefty health warning as you are essentially faking an improvement of resolution. There are a few approaches you could use to fake 10m DEM out of a 30m original. Here's a couple: You could simply use the raster calculator and set the resolution. This is the simplest and crudest approach but possibly the most honest. Essentially ...


2

If you understand the limitations of interpolation of your input DEM there are a number of ways you can do this in QGIS. One is with gdalwarp: Raster -> Projections -> Warp Resize it by multiplying Width and Height with 3 to convert 30m to 10m cells. The choice of resampling method will have a huge impact on your result. The most used algorithm for DEMs ...


2

I am using vector and raster approach to solve it. The script below has 3 input parameters: a) polygons (must be single part), b)output point feature class to store the points most distant from polygon boundary c) tolerance in map units. Algorithm: POLYGON =shape geometry calculate centroid of POLYGON (p1) Define distance from centre to polygon outline ...


2

If i got you, you want to check if your circle can be inscribed inside the polygons.You can do it in ETGEOWIZARD,an arcmap addin, (see pics below) for those polygon and separate those maximum inscribed circles have area greater than or equal to that of your supplied circle-you can use select by attribute to separate those circles(>= your sample circle ...


2

The term master is just a pointer to a commit in git. It will always point to the latest commit on the branch called master. If you have the git repository cloned locally you can checkout a specific historic version by just entering git checkout {sha1} e.g. git checkout 0b9d1dc49b and then run make or trigger a build in your IDE. For the particular ...


2

For that kind of dataset I would argue that would be un-wise and try to reproject-on-the-fly. It can be done with ST_Transform(rast), but if you want to go that road be sure to include spatial extents (rast type can be casted to geom type). As aerial images are mostly for viewing I would suggest to consider using an intermediate step by using a ...


1

I would do a spatial join between your point data and US Counties. If you do not have US Counties, you can download the 2014 Counties here. Then, add both layers into your map. Click Vector -> Data Management Tools -> Join attributes by location Set the target vector layer to your points. Set the join vector layer to your counties. Choose to ...


1

The easiest way would be the following: enable snappig on the line layer that you are using to digitize digitize the line, but finish your sketch before you close it digitize another line, start digitizing at the end of the previously digitized line (using snapping), finish the line at the start of the previously finished line (using snapping) now select ...


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For the moment, no. You can only define the number of segments for the left and right part, separately (see the properties of scalebar in the composer editor).


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write 'D:\ne_10m_airports' as 'D:/ne_10m_airports' (change with uri formalism) or 'D:\ne_10m_airports' (escaping) or r'D:\ne_10m_airports' (r means raw string) regards


1

You could open a ticket (bug report) in QGIS Tracker web site with your problematic data. To do this, read these guidelines With all your data, the developers should be able to fix your problem.


1

You can create a DEM with higher resolution than the original one, just like with any other raster data. The question is, if you really get better informations from those interpolated values. I often do this for "cosmetic" reasons only, e.g. for obtaining a nicer hillshade layer with a less "blocky" appearance in the map. Load your DEM In the layer ...


1

There is no yet package for ubuntu 15.04. A new major version is planned for OTB in the next weeks and then I'm sure that package for 15.04 will be available. Alternative solutions: compile a local version of OTB (I've never tried to use OTB compiled locally in qgis) Standalone version of Monteverdi2 provide also access to all otb-applications


1

Technically not. 30 m is the resolution of the DEM that you have and you cannot derive a higher resolution (10m DEM) DEM from that. Inversely, you can derive a 30m DEM from a 10m DEM.


1

This looks very much like ARCGIS ASCII grid: http://en.wikipedia.org/wiki/Esri_grid http://www.gdal.org/frmt_various.html The additional data should be placed at the top of the tabular data. Then both QGIS and ARCGIS are able to read the data. The corner coordinates look like degrees, so EPSG:4326 should be the right CRS if you are asked for it.


1

Images can only contain full pixels. Keeping both the the pixel size and exact clipping area is only possible if the clipping area is multiple of the pixel size. You can keep 200 by 200 pixels with 2000x2000 meters sized output but not if the output area is 2001x2101 meters. By default the area is kept accurate and pixel size is adjusted. You can alter the ...


1

You can (sort of) achieve it by altering the QGIS layer tree model. Write the following code snippet in a QGIS Python console: root = QgsProject.instance().layerTreeRoot() model = QgsLayerTreeModel(root) model.setFlag(QgsLayerTreeModel.ShowLegend) model.setFlag(QgsLayerTreeModel.ShowLegendAsTree) model.setFlag(QgsLayerTreeModel.AllowNodeReorder) ...


1

Sassá, i'm not an expert but here's what i would do : At startup maintain a lookup table containing the layer id and the corresponding name u want to be left unchanged. Then i would use the layerNameChanged signal with a line of this kind : self.curLayer.layerNameChanged.connect(self.watchName) u do that for every layer of your project. then in the ...


1

You can reference/embed the layers from a second file. (by using the "Layer - Embed Layers and groups" menu entry) Layers that are embedded like that are read-only (so you can't rename them). You can move them around temporarily but those changes don't get saved.


1

I just found it myself - it's under layer properties -> General -> Data source encoding.


1

There are a couple of ways of tackling this problem. The first is to try and find a tool to do the job. The second is to use a bit of Python scripting to do it manually. Since finding tools seems to be hard, here's a python solution. You'll need to figure out how to install python/gdal/numpy yourself, but once you do you won't be disappointed. It's ...


1

Change variables indir and outdir according to your need. The code will find each file with extension 'txt' in indir and every subdirectory of indir. If you need another coordinate system than EPSG 4326, please change the EPSG number in line 9. The converted files will be written to directory outdir. import os indir = 'G:/LANUV' outdir = 'G:/LANUV' for ...


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Please try to change the second part of the SQL-Statement: e.g. update lidar_pts set z= st_z(GEOMETRY) It worked fine for me with mulitpart-points - documented here http://isticktoit.net/?p=1117


1

QGIS does not write its log messages to a file by default. If you have a debug build (nightlies normally are) they are written to stdout. That means that you run it in a terminal on linux you will see the messages there. On Windows I think there is a tool called Debugging Tools for Windows or similar that can intercept the messages. An alternative is to ...


1

Might sound obvious, but I've found it useful to make the QGIS messages box a floating dialogue so that you can extend it from top to bottom of your screen. This would allow you to see and print screen more messages when QGIS crashes. Sorry, I don't know where QGIS writes these messages.



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