Questions tagged [values]
The values tag has no usage guidance.
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Displaying specific field values of attribute table in QGIS Print Layout
I am building a layout where I want to add the attribute table of the map and only display the maximum and minimum values of a field. I think there is the option to filter by expression but I am not ...
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How to generate values and create a heatmap from 3 different point vector layers in QGIS
I am new to QGIS and would like to turn what I have into a heatmap.
I have 3 different sets of points that go across the map of a UK (see the image attached) that represent coastal marine habitats. ...
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Select points with maximum value in each polygon
I have Census areas as polygons and Census population counts as points at a lower geographic level (i.e., there are many points within each polygon). I need to select 1 point from within each polygon ...
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37
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I can't update any attribute values in PyQGIS
I've been using PyQGIS for a few of weeks. I'd write a script which shows all earthshakes responding to given parameters, so I wrote this code:
from PyQt5.QtGui import *
from PyQt5.QtCore import ...
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Reclassify by table
I'm using IFSAR 5x5 DEM Raster and run a Reclassify by Table with only 5 values 1, 2, 3, 4 and 5. Then I converted the reclassified raster into Polygon. When I checked the attribute table the values ...
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QGIS Value Relation Widget saves not the KEY COLUMN values but the VALUE COLUMN values in the attribute table
As far as I know, the "Value Relation Widget" is supposed to store the records from the field designated as KEY COLUMN in the attribute table, while the records from the field designated as ...
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252
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Importing CSV results in NULL values for decimal column in QGIS
I am importing a .csv file and one of the "integer" columns ("ZVH Density") is all NULL values when imported as a Delimited Text file. Whole numbers import (known through trial and ...
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I am trying to produce a LULC using supervised classification , but I got an out-put in gray color
I am trying to produce a LULC using supervised classification , however, I am getting an output in gray color. Anyone knows what is the issue?
// Supervised Image Classification with Landsat 8 ...
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193
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Connecting points to the two closest highest values grouped by category
In a points layer with the fields "POP" (corresponding to the population value) and "CATEG" (corresponding to municipality id), my goal is to connect the points of each ...
- 2,419
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95
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QGIS attibute form with value relation avoiding table
Is it possible to use some expression or text containing a values list for the dropdown control to display them?
The goal is to use a short list of values and not have to create a related table for ...
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How to recover parent value while creating parent and child layers in a embedded forms setup?
I read the documentation, examples and made many attempts, but I still can't make this work.
What I want is to get a value from a parent layer while editing a child layer, when both features are being ...
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86
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QGIS 3.22.16 Bialowieza. Selecting matching value in 2 fields
I am using QGIS 3.22.16, I try to select similar 'null' value in 2 different field. I tried the solutions suggested from one this exchange.
Selecting features with equal values in different fields in ...
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124
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Autofilling based of value map in QField
Is it possible to prepare a Value Map with autofilling? I have a list of almost 500 plant names and it is difficult to find correct name on my device (phone with Qfield) while scrolling. Is it ...
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383
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QGIS 3.22: problems with dropdownlists (attribute forms)
I discovered the nice possibility in QGIS to create dropdown lists in a field, with which I (should) choose in a simple way one of several species (in my case) - while entering new features. I tried ...
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531
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Display expression of layer if geometries intersect in QGIS [closed]
I'd like to display the value of a layer (polygon with parcels) only in case a line (f.e. a river) intersects, crosses or touches the polygon of the parcel by using the expression dialog... but I ...
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Extracting minimum pixel value from multiple rasters
I am trying to extract minimum values from about 300 raster files (GeoTIFF) - for example an output table containing raster names against their minimum values. I would like to automate the process. I ...
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How to highlight by gradient specific range of values from the same field in QGIS?
There is a field about alcohol consumption by country with 10 max. and 10 min. values (picture 1).
Need to choose only 10 max. values and create a gradient map. Seems its needs to be some expression, ...
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737
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Setting default value in QGIS field using QgsEditorWidgetSetup in PyQGIS
There are many questions like this but either they propose to implement a new method to update values or describe how to set default values for fields in GUI.
I'm writing a QgsProcessingAlgorithm and ...
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Alternate view to normal view in attribute table [closed]
I have somehow accidentally changed how my attribute table looks and I dont know how to get it to go back to the original state has anyone any idea how to change?
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469
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Invert raster's min with max values (as well as the in between values) and vice versa using R
I have a raster with pixel values, 1 to 255 (no decimals). I want to invert their values in a way that pixels with value 1 will get value of 255, pixel with value 2 will get 254, pixel with value 3 ...
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136
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LANDSAT-7 strange strip on SWIR bands (B5 and B7)
I was exploring Landsat 7 data on SentinelHub and came across with this strange strip in the SWIR band B7 (also B5):
By placing a pin in this strip and exploring the stats, I found that there is no ...
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How to get the number of pixel with a given value from a RasterLayer in R?
I'm working with Corine Land cover data. I want to assess the number of pixels with any forest value (311, 312, 313, 321, 322, 323, 324) of two reference years. That's wat I did:
clc00 <- raster(&...
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Nested for: I execute changeAttributeValue in the outer loop, print it and is still NULL... but inner loop works kind of fine?
A bit hard to explain, untill now my script is:
I have a for, where:
if an "Analized" attribute is NULL, I will change it to "Parent",store a "Join Value" attribute in a ...
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108
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Extracting average value at point using ArcGIS Pro
I have a dataset of over 500 points that represent the location of a number of site boundaries and a Tif file displaying the wind speed data over the study area.
Is it possible using ArcGIS Pro to ...
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119
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pH = 0 in pH layer
I have downloaded the pH layer from ISRIC database. However, when I added it to QGIS, I found it contained lots of points with the values = 0 (red points in picture).
Can I treat those 0 values as NA?
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Sorting dictionary values and getting sorted keys in new dictionary using Google Earth Engine
How can I sort a dictionary's keys in Earth Engine based on their values?
For example, I have such a dictionary defined in Earth Engine after some calculations and I want to sort that based on ...
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407
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Classifying raster layer by number of equal values in given area using QGIS
I am using QGIS 3.16.12 - Hannover. I have a binary raster layer which consists of 2 values, either 0 or 1 (in my screenshots, 0 = black, 1 = white). The 1 values are scattered throughout the layer in ...
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423
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Changing raster pixel values outside of polygon box using rioxarray
How do I change all raster pixel values outside of a polygon (keep the original values inside polygon) into a certain value?
I have passed through rioxarray clip() like below from this link:
...
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83
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Projecting raster changes the range of values
I am trying to project a 1 second DEM from GDA94 to UTM56 in ArcMap using the Project Raster tool. I tried different methods: bilinear, cubic, nearest neighbor. Nevertheless, the values of the output ...
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119
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MOD04_L2 data processing in r
i am new to using r, so i excuse in advance for asking basic question. I have been trying to convert MOD04_L2 data into GeoTIFF and extract value to a district shapefile in R. the coding seems to work ...
