New answers tagged

1

The tutorial in the answer posted by Venug uses the Raster > Miscellaneous > Merge functionality. What I don't like about that method is that it requires you to find the files you want to merge in your file system. This can be tedious in a directory with hundreds of files. I prefer to use the Processing tools, which use the layers as inputs. Here I have an ...


2

I hope below link will help you to complete the task as you want.. http://www.qgistutorials.com/en/docs/raster_mosaicing_and_clipping.html


0

If you don't have to work in an ESRI workflow you can try the gdal merge tool from the GDAL toolset (http://www.gdal.org/gdal_merge.html). I'm pretty sure this will allow you to use floating point numbers for your resolution. I've had trouble with this tool if you are using very large rasters but if they aren't too large it can work well.


3

Were the original pre-merge lines all pointing in a sea to source direction? If not then merging multiple lines flowing in opposite directions will cause the problem you are seeing. The solution is before you merge, you flip the lines that need flipping so they all flow from a source to sea direction.


1

Here is a step-wise process. Queries were made with Spatialite-gui and visualizations with OpenJUMP. Take some points into table "points" with an attribute "radius". Buffer points by taking the radius from an attribute with SQL CREATE TABLE "buffers" AS SELECT ST_Buffer("geometry", "radius") as geometry FROM points; Union the buffer areas with SQL ...


1

You could to use Dissolve Tool But, perhaps you could to create a buffer using the parameter: Dissolve result=YES


0

In SQL, it is an aggregation query. You can do something like: Select st_Union(geom) from your_table group by the_attribute_which_make_each_group


2

In QGIS you'd use the merge shapefiles function, just be sure to choose the correct couples/triplets/whatever. From the program menu, Vector -> Data management tools -> merge shapefiles


2

Assuming there is a common field between them all: Merge all the feature classes together into one feature class Dissolve the feature class based on the identifier field. This will result in a multi-point feature class with each entry comprised of multiple locations Run feature to point to collapse the multipoint to point


0

If you're using ogr2ogr to load data, you can simply apply the append tag. -append Other than that it will depend on the solution you are using. The more common solutions for loading MasterMap data are: Go Loader FME


1

Layer stacking is a process for combining multiple images into a single image. In order to do that the images should have the same extent (number of rows and number of columns), which means you will need to resample other bands which have different spatial resolution to the target resolution. In other words, all images/bands should have same spatial ...


1

You could install the Merge Shapes Plugin and then merge all polygon layers (Shapefiles) within an input directory:


0

After several tries I had a solution for the problem. I'm still not perfectly satisfied with the result but it does what it has to. It creates a list of IDs and REGION IDs. If I Join this CSV to the shapefile I can use Dissolve by REGION ID and that's it! I've created a tool of it in ArcGIS. It may help someone so I copy my code here: import arcpy import ...


1

Load your files into Qgis. ( via add layer - raster ). Merge your rasters with the raster function "Merge" (menue raster). Use the function "Clipper" from the raster menue. Within Clipper you can set the extend to your bounding box coordinates.


1

You can do this with ST_ClusterIntersecting: SELECT attr, unnest(ST_ClusterIntersecting(geom)) FROM lines GROUP by attr;


0

You have gdal_merge in Menu >> Raster >> Miscellaneous >> Merge.. Here is a training page in the QGIS Help file.


0

For merging rasters, QGIS use the script gdal_merge (Python script) gdal_merge.py raster1.tif raster2.tif raster3.tif -o merged.tif Merge method is for the QGIS tool under Vector -> Miscellaneous -> Merge merge vector layers, as its name indicates


1

I am trying to do the same as you in QGIS 2.14.1 and I am also having trouble. The native "dissolve" included in QGIS didn't work for me. The way that worked for me was using the GRASS function: Process --> Toolbox --> (in the sidebar) GRASS --> v.dissolve --> and follow along... I hope it helps someone.


0

The original canopy rasters have a nodata value of 255 ( not zero) outside of the exact 3-degree extent. You can check that with gdalinfo on command line, or inside QGIS with Rightclick on the layer -> Properties, Metadata tab, Properties section. So it works for me with: gdal_merge.bat -n 255 -a_nodata 255 -of GTiff -o F:/Karten/Geotiff/NLCD/out.tif ...


0

Try to check No data value = Zero, and see if that succeed, as shown below If it is not zero, then replace the zero pixel value with value of pixel. Another option, would be to go to the Transparency tab, and add 0 as an Additional no data value or the pixel value of it is not Zero.



Top 50 recent answers are included