Questions tagged [statistics]

Collecting and analyzing numerical data or making numerical summaries of data.

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Chi-square between rasters

I have two rasters (both with 10 m * 10 m resolution, for an area of approx. 1 000 km2) with the following variables. Both are categorical. A) Habitat type with 9 different classes. B) Soil moisture ...
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Storing movement vectors in DB

I'm not sure if this question is applicable to here or the stats exchange. Maybe some GIS folk have taken a good look at GIS stats? I've got a postgres+postgis+timescaledb database that has billions ...
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Calculate statistics for multi bands

I would like to compute statistics for a multiband raster. How can I process? This is my code: python if os.path.isfile(_tmp_path_raster): dataset_raster = gdal.Open(_tmp_path_raster, ...
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2 votes
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67 views

QGIS starts a query "ST_SummaryStatsAgg()" on PostGIS3.0 for a raster and needs more than 10min to load

I am working on a test-server (RAID6) implementing PostgreSQL/PostGIS with vector and raster support. The aim is a big database sharing different data types including high resolution (0.5m, also 0.1m; ...
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Finding average value of field within selected set of points using ArcPy with ArcGIS Pro

I have a large set of points in my map and a few masks which create a grid system. I want to find the average value of one field for all the points within each grid square. I already figured out a ...
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Do you need to factor in projection into area calculation in Google Earth Engine (GEE)?

I'm interested in calculating the area I have classified of a certain class. Do you need to account for projection to assess class area or can you run the following code and it will be accurate? I'm ...
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2 answers
46 views

Finding max value in field using ArcPy

I have a table and I want to find max and min value in specified field (f1) with their names. I used this code but I only could print max and min values in f1. How can I print their names Like the ...
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1 answer
74 views

Calculating mean of full pixels within a box in ArcMap or ArcGIS Pro?

I am trying to calculate the mean of pixels within a boundary. I am able to find the mean using the calculate Statistics and Zonal Statistics as a table GP tool in ArcMap. But, the issue is I would ...
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How to find if a non-random subsample of a raster is significantly different from the raster using ArcGIS 10.7

I am attempting to find a way to test if the values from a non-random sample of my raster values is significantly different from the raster values as a whole. In this case, I have extracted values for ...
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adjust visualization parameters as parametric values

i want to define visualization parameters for maps as codes in main coding space not as import record for this, i want to calculate the min and max values of image and set them in visualization ...
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1 answer
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Calculate Average Vector Value Based on Points in Polygon

I initially had two layers that I "joined attributes by location." Now I have one layer. In this layer I have several points with values from 1 - 10 and several polygons that are census ...
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Calculate coverage of class types in GEE

I want to define coverage of each land cover type in my study area in Turkey-Isparta. I call ("COPERNICUS/CORINE/V20/100m/2018") dataset and restrict it for my region as below (I load ...
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Counting number of events from CSV file that occurred in corresponding polygon feature class using ArcMap

I'm trying to figure out how to count the number of drought events per county over the last 70 years we've had in NC and am having some difficulty. I downloaded a CSV file from a NOAA website that ...
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1 answer
25 views

Point layer data frequency within a raster layer

I need to determine which land cover has the highest/lowest number of points from a delegate point layer. I have the land cover classified and a separate key (i.e. 1-saltwater) -- How can I find how ...
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174 views

Grouping attributes based on other field using ArcGIS Pro

How do I group my attributes and show total area of districts or number of blocks for each contract? I tried to use groupby clause in select by attribute tool but it did not work. I work in ArcGIS Pro....
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Updated field is null using PyQGIS [closed]

I am going to calculate SPI values for a field in PyQGIS. I created expression for the standardized the values. Stdev and mean values getting correctly. But after update the layer, the new field is ...
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Finding mean and stdDev of vector layer field using PyQGIS [duplicate]

I am going to standardized a vector layer field in Python console in QGIS, for that I want to get mean value and stdev value of the field. How do I find mean and stdev in using PyQGIS. I tried this. ...
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Finding average value from polygon areas in fishnet cell based on lat/long of points using ArcGIS Pro

I have created a fishnet of 0.5x0.5degrees and wanted to know the average lat/long in each cell in ArcGIS Pro. How could I accomplish that?
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QGIS LecoS edge length

I am using the LecoS plugin to analyze areas I have previously mapped. The problem is, that these maps are square, which means, that the areas inside are cut. e.g. the forest continues but I have only ...
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3 answers
51 views

GRASS - Calculate 90th percentile of a timeseries dataset

How can I calculate the 90th percentile from a registered timeseries dataset of 30 rasters in GRASS? GRASS timeseries has 2 "statistical" commands which are t.info and t.rast.univar. ...
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7 votes
2 answers
371 views

Calculating percentage of number of features in layer in QGIS

I'm using QGIS to get some "stats" on a current layer e.g. to determine the number of features of a certain class. That I do by using the Aggregate-Algorithm on the class-attribute with ...
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Setting up Generalized Linear Regression in ArcGIS Pro

I am analyzing a series of old canals and I am trying to make the case that these are tied to certain physical characteristics (soil, slope, etc) in the watershed. To check wether or not my hypothesis ...
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How to control for population density?

My project requires me to control number of stores by population density in each neighborhood. For instance, suppose I know neighborhood A has 10 stores and a population density of 100 people/sq mile ...
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1 answer
93 views

Finding percentage of raster contained in shapefile using ArcGIS Pro

Using ArcGIS Pro, I have a raster that shows tree height and a shapefile that contain parcels of land. I am trying to find out the percentage of the raster that intersects with the shapefile for each ...
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1 vote
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Choosing geospatial statistical test using building characteristics and distance together

New to geospatial analyses and I am trying to assign a building footprint to be a type of building (e.g., industrial building). In another dataset, we have determined the average building area, ...
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1 vote
1 answer
418 views

Calculating Percentiles on a vector layer in QGIS

I have a vector layer in QGIS with various numeric fields and I would like to calculate the percentiles, 90-95-99, for each of the fields. I have tried the GRASS v.univariate algorithm but this only ...
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1 answer
64 views

Summarizing table based on 2 columns using ArcMap

I got a shapefile that has the landuse and the area of every single piece of ground near a specific road. Like this: I want to summarize all landuse areas of near each road in one row. Like this: ...
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1 answer
53 views

Regression between reflectance at pixel value vs input daily data over image collection

I have been trying to make a raster of regression values between reflectance value vs input data at each pixel position in a collection (So, for example the R^2 relationship between daily average ...
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1 vote
1 answer
232 views

Percentile Composite of Collection in Google Earth Engine

I know how to find percentiles within a single image, but is there a way that I can make an output image that is a percentile composite of an entire collection? E.g. a composite image where each pixel ...
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1 vote
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46 views

How to quantify the similarity of spatial patterns?

I am not a GISer, but I do believe a GIS (more specifically, spatial statistics) algorithm could help with the task I am carrying on. If posting a question that has already been posted (by me) on ...
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1 vote
1 answer
35 views

Delete fields from a table based on Mean calculation using ArcPy

I have an attribute table with 100 columns (values are float and not NULL; more than 3000 rows). Using ArcGIS 10.6 I want to calculate the mean value of every field in a shapefile separately (like ...
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Spatial similarity test between daily raster datasets

This question is an extension (next step) to Comparison with different resolution rasters. Currently I have successfully compared the similarity between the two raster datasets (currently both rasters ...
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9 votes
2 answers
285 views

Exporting features when column value between specific percentiles

I want to do a statistical analysis. I need to export some features. Their column value between 10%-90% (or 20%-80%) percentile in order to avoid outliers' effect. I can't find a function in the ...
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2 votes
1 answer
52 views

Summarizing Attributes in ArcGIS Online

I need to find a way to summarize an attribute in ArcGIS Online. I know it is a simple task in ArcGIS Pro where one just needs to look check the statistics and look at the properties section. However, ...
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1 vote
2 answers
71 views

Finding average of values assigned to a field

I am using ArcGIS Pro. I have an attribute table with point data of the amounts of time it takes a vehicle to reach its destination. Each destination is assigned to one of three zones and each ...
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400 views

Adding rows in attribute table together using ArcGIS Pro

I am using a parcel map and I have a layer with a ton of polygons and those polygons have different names. I combined all the names into categories in the symbology tab but when I go to the attribute ...
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1 answer
120 views

Dissolve with stats in Python for QGIS

I’m using QGIS 3.10, PostgreSQL 10 and PostGIS 2.5. I want to dissolve within a Python script a shapefile so that the result is dissolved by one field and the number of different values of another ...
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-1 votes
1 answer
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Ranking polygons within feature class by group and by area in ArcMap [duplicate]

I have a polygon feature class with attribute fields 'name', 'rank' and 'area' in an Esri file geodatabase. For each name there are multiple features (polygons) in the feature class. So let's say 5 ...
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39 views

QGIS graphical modeler and statistics tables

I have been able to use a processing tool available in QGIS, 'Statistics by Categories'to obtain some statistics for lengths of pipes of different materials within a polygon area. I am only actually ...
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2 votes
1 answer
125 views

Statistical validity percentage check on raster

I would like to check if my set of NDVI images with min/max values from -1 +1 is good for at least 80%. I took my cue from this other topic: here. Considering that the nodata is -32768 But the values ...
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Calculating summary statistics of table while prioritising certain values

I have a data set of species each of which is assigned a score, for each spatially joined location (grid square) I need to find the sum score of unique species. There is a complication in that ...
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Obtaining weight of evidence plugin for ArcMap

I read this article: An integrated user-friendly ArcMAP tool for bivariate statistical modelling in geoscience applications but I did not find this tool "bivariate statistical modelling , BSM &...
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1 vote
1 answer
100 views

Wrong minimum in layer properties when displaying raster with classified symbology in ArcMap

I display a raster in ArcMap with classified symbology. ArcMap calculates a minimum of 274,9 for this raster. However, this raster has at least one pixel with value less than 274,9 as the information ...
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1 vote
2 answers
105 views

Calculating mean value with field calculator for selected records using ArcPy

I want to calculate the mean value in the field z which has Type Zero and write it in Ground field. How can I do that with arcpy? arcpy.MakeFeatureLayer_management(Shapefile, "layer") ...
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1 vote
0 answers
70 views

Autoregressive moving average (ARMA) model in GEE

Is there a way to implement an autoregressive moving average (ARMA) model in GEE? For example, for MODIS NDVI dataset spanning 1 year: var modisNDVIcoll = ee.ImageCollection("MODIS/006/MOD13A2&...
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2 votes
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110 views

Calculate average elevation value in LAS files in a specific area [closed]

I need to calculate the average elevation and its standard deviation of some buildings and parts of roads using LAS files. I want to be able to consider only the points that are within a polygon in a ...
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2 votes
2 answers
374 views

Python Script for Zonal Statistics As Table results empty Table

I have a TIFF format file and want to automate some tasks. I have a Python script for Zonal Statistics as Table but it results in empty table output. However, the Zonal Statistics As Table Tool at ...
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2 votes
1 answer
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Statistical method to quantify the accuracy of point clusters

I have coordinates of about 13 points from different pictures in UTM. Per point I can have 2, 3, 4 or 5 coordinates of these points from 2, 3, 4 or 5 pictures. I would like to quantify the quality of ...
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26 views

How to find all cells within a neighborhood with slopes towards the center?

I would like to iteratively go through each cell in a raster in arcGIS that meets criteria (already established as per below description) and find the percentage of cells in a several km neighborhood ...
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2 votes
2 answers
841 views

Count number of features that matches a (minimum) value for each group (id)

Context In FME I want to count for each group (defined by a "group by" id in any kind of aggregation-like transformer, such as the StatisticsCalculator), how many occurrences equal to a ...
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