6

You can use the SQLite function row_number() for that, see this example: SELECT ROW_NUMBER () OVER ( ORDER BY name ) RowNum , name, ST_StartPoint(ST_Line_Substring(geometry,0.5,1)) FROM "test" with this result:


5

The spatial prediction aims at predicting a variable where it has not been observed. Therefore you need to know the coordinates of the location where you make the prediction, even if the coordinates are not explicitly used to build your predictive model. Based on your example, you need to know the coordinate of your point to compute the distance to a feature,...


5

Just to add to what @Kostas VI. mentioned: Measuring means always approximation. If the approximation is "good enough", you would consider it "reliable data". What that exactely means has to be decided in each individual context. As general rule: if the data has higher resolution than the minimal size you need for your task, it's probably ...


5

A solution using PostGIS alone. The Steps are as follows: Generate clusters from the points Get the centre of each point cluster Generate a line that connects each cluster centre point (will also approximate the centreline of the route) Create sampling points at 20m intervals along the line (allowing for 10m radius buffer from each sampling point) Get an ...


4

I think it depends on what you want to do with it and what the image depicts. For example, a satellite image depicting Ocean Color (e.g. Sentinel-3 OLCI product) or Sea Surface Temperature (SLSTR product) can be considered continues, since the variables they depict are inherently continuous variables. However, if you wanted to discriminate between some ...


4

As I did not find a good solution, I set out to write it by myself. I started with a routine to detect the outer cells to exclude them from the interpolation mask. Then I discovered that I could not get rasterio to fill the no data cells for reasons beyond my comprehension. I therefore included a custom interpolation as well. It will be slow for large ...


4

The solution presented here consists basicaly of the following steps: Project the points to the line layer Create a new point layer with points at a regular interval along the line For each point of step 2, find the closest point from step 1: this one is the "cluster center": the point that remains and that gets the mean value of the other points ...


4

I have found this question recently and I took it up as a challenge to create time-series linear interpolation in GEE as an alternative to moving average method as demonstrated. I am sure this is NOT efficient but (so far) I also cannot find an alternative solution. Code Explanation The code calculates NDVI value from Sentinel-2 Surface Reflectance from ...


4

In your example of y ~ x1 + x2, x1 is an independent variable this is perfectly collinear to the lat lon. X2 is also perfectly collinear to the spatial variables used to calculate the amount of greenspace. So, I would say that y ~ x1 + x2 is a non spatial model with perfectly multicollinear, omitted, spatial variables. You could create a spatial lag model (...


3

Elevation is major factor in air temperature pattern, for small study area it is better to a) derive regression equation Temperature(Elevation) which in theory should show 6 degrees drop per 1 km of elevation, b)apply it on elevation model and c) forget other two factors, i.e. latitude and longitude or interpolate residuals i.e. deviations from Temperature(...


3

Try this. It works by converting the raster out to a data frame of x,y,value columns, making a spatial points data frame, extracting the missing and non-missing points, fitting on the non-missing points with prediction on the missing points, and then filling in the missing points with the predictions at the missing points in a new raster: library(raster) ...


3

There is a python script "gpx_interpolate" on Github which will do interpolation between GPX track points. python3 gpx_interpolate.py -r 50 -d 3 INPUT.gpx This will output a new file INPUT_interpolated.gpx with 50m (-r 50) between points and along spline of degree 3 (-d 3). Options: Resolution -r: distance between interpolated points. Default is ...


3

I have recently came across the same issue. For example, in one raster data, I have two nodata values: 1.7976931348623157e+308 3.4028234663852886e+38 I used gdalwarp to set them to a unified nodata value: gdalwarp -srcnodata 3.4028234663852886e+38 -dstnodata 1.7976931348623157e+308 input.tif output.tif Similarly, you can reset multiple nodata values (e.g. ...


3

This should work using Shapely and its centroid logic. >>> from shapely.geometry import LineString >>> line = LineString([(-99.156916, 23.731817), (-99.131389, 23.746944)]) >>> line.centroid.x -99.14415249999999 >>> line.centroid.y 23.7393805 If the linestring has multiple points, you could do something like this: from ...


2

I think the easiest way would be for you to draw a polygon that defines the bit you don't want, and use st_difference to subtract that from the canada.map polygons. Then apply the same process you have done with that new polygonal region to get a new grd. Here's how to draw a polygon and then cut it: plot(canada.map$geom) # (add your data point to the plot ...


2

At this point: data.yield.sf <- st_as_sf(data.yield, coords = c("long", "lat"), crs = proj_lambert) the numbers in data.yield$long and $lat are lat-long degrees, but you are creating an sf object with a crs of proj_lambert. This won't change the numbers. You need to create this with a lat-long crs parameter, probably EPSG:4326,...


2

As far as my knowledge goes, spatial interpolation is one of the most-used spatial prediction techniques that researcher are using for both spatial pattern recognition and predicting the behavior of natural phenomena in study area. Consider air pollution as an example that scientists need to predict in a specific urban area when they observe quality indexes ...


2

David it took some time, but I managed to get the correct data for you using the TIN Interpolation Tool. However, there is a catch. During my research I came across this article from September 2019 on Github where somebody had the same problem having e+ values using QGIS 3.8.3. https://github.com/qgis/QGIS/issues/31970 In this article the statement was ...


2

You can use Combine tool to combine the two rasters of temperature and elevation. The combine tool: Combines multiple rasters so that a unique output value is assigned to each unique combination of input values. Although in your case, maybe, you don't want to create a new raster with unique values for the combined rasters, but at least you can see both ...


1

It would not seem to be logically possible unless you have a terrain dataset. height is not a uniform characteristic that can be generated since the values you have are probably need to turn into ranges and don't have a straight progression so then you would need algorithms using intervals. You could use some type of gap filling on a triangulated network ...


1

I believe the issue is to do with your input, it's a CSV file, which is simply a text file not a spatial dataset such as geodatabase featureclass or shapefile. Firstly as as @Nick hints your code is missing the workspace environment setting so it does not know where in_Table is. Either make it a full path string or set the workspace. Secondly you construct a ...


1

Try aggregate (in the first case) and disaggregate (in the second case) functions from the raster package. Note, the argument fact in aggregate and disaggregate can take 2 forms as described in the help page of these functions: Aggregation factor expressed as number of cells in each direction (horizontally and vertically). Or two integers (horizontal and ...


1

A naive IDW implementation, from the top of my head: UPDATE <points> AS itp SET "Z" = ( SELECT SUM(z/d)/SUM(1/d) FROM ( SELECT smpl."Z" as z, ST_Distance(itp.geom, smpl.geom)^<P-value> AS d FROM <point> AS smpl ORDER BY itp.geom <-> smpl.geom WHERE ...


1

Update It is inappropriate to interpolate over a large area, such as a cloud area. Since you have time series data, the data in the mask area is calculated and replaced in the previous image. And then ou can use RASTERIO on google colab to handle raster image. If you need to interpolate some areas, you can use the module below. https://rasterio.readthedocs....


1

If you have a linestrings layer with Z dimension, use the Drape (set Z value from raster) algorithm to assign the Z dimension from the raster to each vertice of the linestrings. But there is not an interpolation there, the vertice will get the Z value of the pixel in wich it belongs. Then, you can densify the lines to get other vertices with their Z ...


1

There are many ways to tackle this problem. An easy path The simplest i can think is to use any point-to-raster interpolation followed by raster-sampling. Any Gis software should do it. I would say SAGA is a good choice for this process. Saga can make ordinary krigging (under "geoprocessing" -> "spatial and geostatistics" menu), and raster sampling (...


1

My advice is to run the algorithm via the gui from the processing toolbox first. Then check the processing history (clock icon at top of processing toolbox) to access the syntax for its Python call. E.g. you will see something like: This can be simplified a bit, so for your code you could do something like: infile = os.path.join(scratch_folder, "lakes.shp"...


1

Here is a worked out CV example using the meuse dataset: # Load Libraries library(data.table) library(ggplot2) library(viridisLite) library(sp) library(gstat) # Settings seed=123L # Convert data to SpatialPointsDataFrame data(meuse) coordinates(meuse)= ~x+y # Log transform meuse$logZinc=log(meuse$zinc) # Save data.frame meuse.df=as.data.table(meuse) # ...


1

To get a sloped 'plane of best fit', try Polynomial regression tool in the Processing Toolbox > SAGA > Geostatistics. Below, the image shows the elevation data (elev) stored in the attribute table. Activate Polynomial regression tool and choose Simple planar surface from polynom options. It will create a fitted surface grid and calculated residual.


1

I didn't find a solution to do exactly what I wanted (a color ramp with manual breaks), so here is the fallback solution I used. I decided to create a lot of classes so it almost seems to be a continuous color ramp. At the begining, I had 6 colors breaks so I calculated to have 31 color breaks. I selected Classify as Primary Symbology and I created ...


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