All Questions

1
vote
0answers
14 views

What is the math behind interactive supervised classification in ArcGIS?

I don't mean the steps to do it, that I know, I mean the maths behind this tool. I understand when I set the training samples I am telling the software what class those pixels should be, so I need to ...
1
vote
2answers
38 views

Leaflet - How to show feature properties in a box that is not a popup?

Popup giving features properties are interesting but I would like to make a side bar where properties of a clicked feature would show. I've got the traditional code for displaying geojson features ...
0
votes
0answers
9 views

Wrong projection used in Pathfinder

I am having issues with coordinate systems in post processing. Does anyone have a recommendation of videos to watch or online classes that can help me improve on this? This is my current issue: Data ...
1
vote
1answer
30 views

PyQGIS : Creating a fixed distance buffer from a virtual layer

First off, i'm trying to learn some python to automate scripts for basic tasks i carry out in QGIS (2.18). Below I create a virtual layer (polyline) using the following script: from qgis.core ...
0
votes
0answers
8 views

How to compile/install php-mapscript with PHP7

So, this PR opens up mapscript support for PHP7. Since there is no ducomentation I gave it a try based on How compile/install php-mapscript on Ubuntu 16.04 (although I'm doing it in Debian 9 if that's ...
2
votes
0answers
32 views

How to find how grass's r.viewshed works programmatically?

I want the Python source code of Grass's Viewshed analysis. In QGIS software there is only an .exe file of that algorithm. Although I'm not sure whether it's written also in python or not. Where can ...
0
votes
0answers
23 views

PostGIS - Nearest Neighbour Join to sum values

I have a table of polygons T1 and a second table of points P1 Each point has a value I want to sum the values of P1 for each T1, with P1 being the closest set of points to T1 At the moment the only ...
0
votes
1answer
66 views

Extract longitude and latitude from object in shapefile

I'm new to GIS and (ESRI) shapefile. I would like to extract GPS-Coordinates or longitude and latitude from every object in a shapefile, mainly from polygons. Here is a picture with one of these ...
0
votes
0answers
11 views

Create a valid shapefile with phpmyadmin/Shapefile lib

I'm trying to create a shapefile with the PhpMyAdmin\ShapeFile library. I followed the example in the Github project repository, but I would like to create a shapefile within polygon elements, not ...
0
votes
1answer
19 views

Centroid value extraction of Landsat image collection in Google Earth Engine

I have an NDVI collection wich I have created from the combination of different collections Landsat5 and 7. How can I exctract the NDVI values of the centroids of each pixel, of each image from my ...
0
votes
1answer
36 views

Find the closest Point from a Point which contains the same attribute

I am trying to create python code to iterate through points on 1 layer and find the closest point on another layer (Road Chainages) based on attribute values. I need to limit the search to < 20m ...
2
votes
1answer
19 views

Values on top of each bar of a histogram in QGIS

Is it possible to show the values on top of each bar of a histogram created with QGIS? (I am using QGIS 2.18) I know this post [Is it possible to label bar charts? addressed a similar question years ...
0
votes
2answers
35 views

ArcGIS If/Else with calculation

I am seeking to calculate the variable MASSSTAB through rounding the variable LAENGE and doing some basic math. My codeblock currently looks like this: x = long(round(!LAENGE!, -1)) def ifBlock(m, ...
0
votes
1answer
14 views

R-Scatterplot: How to match palette() to not incrementing color-column

I want to visualize the feature space in my training areas using scatterplots. I use a nested classification schema, so my class values are not incrementing but sorted in categories like 100 (...
0
votes
0answers
33 views

How to find the optimal path between two points [on hold]

I was given what looks a pretty complex cadastre related GIS task. Given two points, I'm looking for such connecting path that: intersects the lowest number of parcels in total and intersects the ...
0
votes
0answers
10 views

QGIS: Calculate shortest route between coordinates from GPX/KMZ

i'm absolutely new to GIS Software and only need it once i guess, so i hope you'll indulge me if i don't express my needs correctly. I have alternatively a KMZ or GPX file with a lot of waypoints ...
0
votes
0answers
20 views

Landsat TM and ETM+ LST Code for Google Earth Engine [on hold]

The Goal is to Get an Automatic Code for Landsat TM and ETM+ Calculation of Land Surface Temperature for a finer(30m) resolution then the supplied LST Products(500m,1000m) Has someone done Similar ...
2
votes
0answers
15 views

osm2pgsql import OSM data in EPSG:27700

I am trying to use osm2pgsql on Windows to import OSM data to a PostGIS database. I want to pass the EPSG:27700 via the --proj option as follows: osm2pgsql --proj 27700 <other options not shown>...
1
vote
1answer
41 views

Circle is ellipse using Open Street Map

Currently I have a problem while developing an app - I use Open Street Map and draw a Circle and pass it to a Python backend, as central point and point on the perimeter on the Circle. Next I am ...
0
votes
1answer
28 views

Duplicate labels in ArcGIS Server REST map service OpenLayers 5

I'm trying to export PLSS grid from ArcGIS map server and I have a duplicate labels in PLSS map service. Using OpenLayers 5 My code mapPLSSTownshipLayer = new ol.layer.Tile({ extent: [-...
1
vote
1answer
19 views

Changing range of natural breaks QGIS

I have a shapefile of population points, which I've categorized to show the difference in size for each point. However, I'm not satisfied with the range of values it has set out (in picture below). ...
-1
votes
0answers
21 views

Raster Data Encryption [on hold]

I would like to encrypt proprietary raster data. How could I do that?
2
votes
1answer
25 views

QGIS 3.0 - Random Points w/in Polygon Expression

I have a polygon layer with 3 non-intersecting polygons(i.e., id=1, id=2, id=3). I'd like to randomly distribute 10 points within each of these polygon for 30 total, to be used as survey starting-...
0
votes
1answer
28 views

How to style 2 columns with 900 combinations without resorting to rule based in QGIS?

So I have this point layer that has 2 columns that I need styled, one of which is owner_id and the other is size. Both are integer fields if it matters. The owner_id matches with an owner name in ...
-3
votes
1answer
37 views

Has online map-based software for survey been developed? [on hold]

I have been reading old threads about this, but I was hoping there might be new solutions to the same old problems. For my research, I need to ask respondents to indicate on a map where they think ...
1
vote
1answer
23 views

Looping through folders and select shapefiles by name using pyqgis

I want to loop through folders and find shapefiles which contains the name "GST" and merging them together using python in QGIS 3.4.3. In detail: The folder x contains four folders called VA72, ...
1
vote
0answers
28 views

DEM gap filling with QGIS

I have a DEM, geo tif, Float32 whith some gaps. Pixel value relative to the gaps is indicated in the metadata as -9999, but if I click on these pixel with the identify value tool -9999.96 is shown. I ...
0
votes
0answers
16 views

QGIS SCP plugin: Band calc errors

The Band Calc tool in QGIS' Semi-Automatic Classification (SCP) plugin returns errors, even though the source rasters are valid. For example, I have dividing Band1/Band2 (landsat 8) returns a raster ...
2
votes
0answers
40 views

Does the Clipper plugin for QGIS work with Shapefile layers?

I created 2 overlapped polygons in one Shapefile layer, run the intersection tool with another layer and then run the Clipper plugin. This causes the error: TypeError: MultiPolygon geometry cannot be ...
0
votes
1answer
39 views

Delete vertices on polygon feature class, based on the intersection with point shp with python

I need to delete some vertices from some polygon fc that are unnecessary for the geometry. I have a point shapefile that contains all unnecessary vertices as points - but how can I access the vertices ...
1
vote
1answer
33 views

Iterate Feature Classes + Truncate Table = Empty output

I am trying to make a model that basically updates an original file with new data. I do this by using a mask to "erase" old data and then "merging" in the new data, however this creates a separate ...
1
vote
1answer
10 views

Cannot find header files after installing QGIS with apt on Ubuntu

I followed the Official Install Tutorial and installed QGIS2.8 or 3.0 using sudo apt-get install qgis python-qgis. I did not install python-plugin-grass because of dependency problem. The QGIS client ...
0
votes
0answers
6 views

MySQL group union

I want MySQL to merge many geographies together to form a single shape. A zipcode table has a row 'shape' containing a perimeter from Uncle Sam. Definition here: https://www.db-fiddle.com/f/...
0
votes
0answers
13 views

Download OSM data with QuickOSM and QGIS Modeler example and/or tutorial to share

I would like to automatically search and save my results (11 layers) via the QuickOSM plugin using the Qgis Graphical Modeler. Could anyone help me with some already prepared example or some tutorial ...
1
vote
1answer
21 views

Uncaught SyntaxError: Unexpected token < (Geoserver popup in leaflet using ajax)

I am trying to show attribute information of features in a popup from my postGIS db tables via Geoserver WMS. I have successfully been able to add these layers to the map. However, when I try to grab ...
2
votes
1answer
28 views

Show custom QgsAttributeTableView

I'm setting up a custom widget in a QGIS3 plugin and include a QgsAttributeTableView like this: layer = iface.activeLayer() layer.getFeatures() canvas = iface.mapCanvas() vector_layer_cache = ...
0
votes
1answer
25 views

SQLite spatial function

I have a SQLite database, with point and linestring geometries. Between the points(blue) and the linestring(green) is a gap, which I want to close with another line(red). The line should have angle of ...
1
vote
1answer
32 views

How to delineate these coloured mandals as different shapefiles using QGIS?

The image shown above is everything I have! Is there a way to make separate shapefiles for all the coloured palletts
0
votes
0answers
6 views

Populate Story Map Journal description with attribute table

I am new to ArcGis so please do bear with me. I am using a story Map journal template to showcase my 5 different maps. I want the information of all these map to be displayed in the description box. ...
2
votes
1answer
38 views

Reference ObjectID in a where clause within an UpdateCursor

I have a dynamic list of ObjectID values I need to filter an UpdateCursor on. I am setting a where_clause as: where_clause_points = "[ObjectID] IN({0})".format([x for x in inspected_points]) Which ...
1
vote
1answer
17 views

QGIS Crashes on USB/Storage device Plug-in/out

I am using QGIS Version 3.4.0-madeira on Windows 10, and my QGIS crashes each time, a USB device is plugged in/plugged out, or even any network drive gets disconnected with while running QGIS. This ...
-1
votes
0answers
16 views

DSAS EMPTY OUTPUT

Every time I calculate the Transected File in DSAS (Dgital Shoreline Analysis System), the output table is always empty. Every time I Calculate Change Statistics, a window saying EMPTY OUTPUT. DATE ...
1
vote
0answers
6 views

Label Position Changed In VectorTile Service

I made a map of boundies in ArcGIS Pro, labeled the polygon geometry by it's name. Everything is okay in ArcGIS Pro, but When I publish it to the ArcGIS Portal as a VectorTile Layer some of the label ...
0
votes
0answers
23 views

Importing CSV to shapefiles using loop?

I'm adapting this code to import a folder of CSV files to shapefiles. Error thrown at "for row in reader:" is "ValueError: I/O operation on closed file" Not sure if this means the CSV files closed so ...
0
votes
0answers
6 views

Display a popup with the information arranged in tabs using Mapbox GL JS

I'm creating a map in the Mapbox and I need When you click a point on the map the information is displayed in a popup. So far I can already do following this tutorial: https://www.mapbox.com/help/...
0
votes
0answers
20 views

Importing Excel file into ArcGIS

I am importing Excel sheets into ArcGIS for map-making purposes. I have one column that is not recognized. I cannot figure out what is wrong with it, I have deleted it and remade it, checked the ...
0
votes
0answers
11 views

Conversion to KML won't convert whole layer

I'm trying to convert a vector layer to a KML file. Here's what the layer looks like in ArcMap-- as you can see, it has multiple polygons: Here's my code: import arcpy arcpy.env.workspace = r'C:\\...
0
votes
0answers
12 views

QGIS 3.4 - Access Violation no RTTI data

i'm used to writing in C for embedded systems, so python is somewhat new to me. I've built up this script in QGIS script editor following the template. However, when I run the script I get an Access ...
1
vote
0answers
19 views

WFS how to consume with different coordinate system? [duplicate]

I have a WFS in EPSG:4167. My map view has EPSG:3857. How to make the WFS work on a map view with different coordinates? I used this to define my coordinate system from wfs: import { register } ...
-2
votes
0answers
17 views

Adding Topology to Parcel fabric?

I already have a parcel fabric created with some parcels drawn in. The parcels are accurate and correct. Now I would like to add in a topology. I will be adding more parcels in the future. I have ...

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