Geographic Information Systems

Questions tagged [statistics]

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

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30 views

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 ...
8
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2answers
127 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 ...
2
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1answer
31 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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0answers
18 views

Plot statistics of a raster dataset by latitude in GEE?

How can I plot some statistics of a raster by latitude (see bottom picture) in GEE? Some pictures of a paper are attracting, so I want to know how to reproduce this in GEE or ArcGIS or QGIS or some ...
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2answers
40 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 ...
0
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1answer
52 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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0answers
38 views

How to study the association between categorical rasterised environmental variables in R?

I have a set of environmental variables in raster format where I want to study the dependencies between them. To do so I was thinking of using association tests such as chi-squared test. I want to ...
1
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1answer
38 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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1answer
60 views

Ranking polygons within feature class by group and by area in ArcMap

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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0answers
15 views

QGIS graphical modeller 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 ...
2
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1answer
46 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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0answers
29 views

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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81 views

GRASS Tool r.stats.zonal for QGIS 3.14 Pi is not working in batch mode

I am trying to calculate the averages and standard deviations of the pixels of a group of 31 vegetation index rasters calculated from Landsat images, but only where these rasters intersect the ...
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0answers
27 views

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 &...
1
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1answer
31 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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2answers
49 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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0answers
21 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&...
2
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0answers
38 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 ...
2
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2answers
77 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 ...
2
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1answer
24 views

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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0answers
16 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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2answers
177 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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0answers
48 views

Calculating Nth percentile from table in ModelBuilder of ArcMap

I am trying to build a complex tool, using ModelBuilder and I am new at this. I have two feature classes full of polygons. The first contains 1300 polygons, dividing a city in zones (ex: residential, ...
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0answers
29 views

Calculating rates and classifying polygons with specific values using ArcGIS Pro

I am still relatively new to GIS, especially ArcGIS Pro. I am working on a project where I am trying to find the rate of car crashes along major roads in different census blockgroups. In this ...
2
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1answer
30 views

Find overlapping area of each class in classified images

I have three classified satellite images, lets say 2005, 2010, and 2015. All images are similar i.e. the same total area and same number of classes. I want to output those areas where pixels of all ...
0
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1answer
82 views

Raster info in rasterio module

I have a folder of NDVI raster and I want to see his stats as follows: with rasterio.open('C:\\path_to_NDVI.tif', 'r+') as ds: array=ds.read() stats = [] for band in array: stats.append({ ...
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1answer
85 views

Too many pixels in Earth Engine, and scale parameter meaning

I am trying to calculate stadistics for burn areas based on the number of pixels. When running the code, GEE says too many pixels, I tried to solve it following the guides given by google developers ...
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0answers
27 views

Does GWR only work with point data?

I'm currently working on a dataset where observations are only given very general location information, eg. counties they are in, the whole dataset is on country level scale. I used OLS to analyze and ...
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0answers
21 views

Nan values when classifying with Natural Breaks (Jenks)

When using the Natural Breaks classification mode, "nan values" often appear in the classes (see picture below). The nan values may disappear when I change the number of classes back and forth, but ...
6
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2answers
202 views

Postgis - Zonal statistics - Parallel computation?

I am looking to speed up a postgis query, regarding zonal statistics. I am using postgis 3.0 with postgreSQL 12 and I was hoping that I could apply the below script to speed up processing using ...
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0answers
30 views

How to calculate line raster intersection statistics in ArcGIS Pro

Years ago, I lived by Hawth's Analysis Tools for spatial ecology. Since then I've been having to figure out how to duplicate the functions in ArcGIS 10.x and now ArcGIS Pro 2.5.0. In this case I am ...
4
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1answer
46 views

Setting Bin Count in QgsRasterHistogram

Following this question, I am trying to use QgsRasterHistogram to obtain a histogram of my raster image. However, I cannot figure out how to change bin count. I looked at the docs here, and it would ...
0
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1answer
49 views

Incomplete summary statistics in ArcMap

I am using ArcMap 10.4. I have an attribute table of shapefile with more than 20 millions rows stored in gdb. That table has a column with postcodes (that are often repeated) and column with values. ...
0
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1answer
68 views

Calculating median in grouped data using ArcMap [closed]

I got stuck when calculating the median age in grouped data (age ranges) for each feature (each feature is a single administrative unit). I have about 18,000 features. Field names indicate age ranges:...
0
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2answers
52 views

Generation of pixel statistics in multiband raster [duplicate]

I want do generate for each pixel the average and standard deviation or better the variance coefficient for raster with 57 bands. The average should be average of the value for all bands. The result ...
0
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1answer
150 views

Calculate statistics of raster based on plygon borders in google earth engine

I have a script in GEE that takes shepfile (sometimes with two polygons), classify it to 3 different classes and create one new layer with those 3 classes. I want to calculte statistic for each ...
1
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1answer
59 views

Summarizing Attribute Table Based on Condition

I have a one-to-many joined table (i.e. duplicated AssetIDs with other different attributes), and I would like to consolidate the table (20 records) into one single record. However, when using ...
0
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1answer
400 views

Getting p-values from mgcv GAM result and calculating their average

I'm doing many GAM model calculations (mgcv). Their output looks like the attached image. What I want to do is 1) to get only p-values from the output and 2) calculate their average. For example, in ...
2
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1answer
370 views

GEE, pixel based SD over time series Sentinel 2 NDVI

I would like to calculate the SD of a NDVI value by pixel over a time series using Sentinel 2. It is to identify pixels with more or less variations over a specific time period. The expected output ...
2
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1answer
28 views

Extracting Summary Statistics value with cursor and assigning it to a variable

I am writing a script (to be used in ArcGIS 10.7.1) that uses a Zonal Statistics tool to create an average of a raster that is beneath a grid. I then use the Summary Statistics tool to take the ...
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0answers
40 views

Count of majority value for each cell?

I ran 10 classifications (Random Trees) in ArcMap. Each time the output will be somewhat different. I have made a final map based on the majority value of each pixel using cell statistics (majority). ...
5
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1answer
85 views

Variogram for clustered data point

I would like to study the spatial dependency in my dataset of a variable (crop yield) spread across a country with 250 sites. A first guess was to use a variogram on the data. However, I am not sure ...
3
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0answers
41 views

Statistic for test of significant difference between 3 spatial distributions [closed]

I have three spatial averages of Particulate matter over a certain area as seen below. There clearly seems to be a difference between average PM concentrations for each of these months, but how can ...
2
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1answer
158 views

Styling plot items by category in QGIS print layout

I am making a sensitivity atlas which gives me gridded sensitivity values (A to E) for a given area. I am using the atlas functionality in QGIS 3.10 to create several maps showing these sensitivity ...
1
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1answer
80 views

Raster layer statistics QGIS 3.4 doesn't give information about pixel count

I created a plugin in QGIS 2 AND I used the qgis:rasterlayerstatistics , I could get the 'COUNT' information : pixels number, but when I migrate my plugin to version 3.4 I found out that this ...
2
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0answers
24 views

Getting TIN Statistics in ArcGIS Pro with 3D Analyst

I'm trying to get basic descriptive statistics from a TIN layer (MIN, MAX, MEAN, STD) to compare it to IDW interpolation data of the same study area, but can't seem to figure out how to retrieve ...
2
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1answer
107 views

QGIS “Statistics by Categories” tool greyed out at 3.8.3

I have both 2.18.28 and 3.8.3 loaded on my computer. I have a Geopackage containing a line layer of hiking trails. The attribute table contains two fields: surface_type (text) length_miles (decimal)...
0
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0answers
27 views

Summary Statistics with non-unique Case Field

Is there an elegant way to run summary statistics and only keep a field if it matches the statistical test? For example, I have some points, and distances from these points to several polygons. I run ...
1
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1answer
161 views

Grouping wildfires dates by season and getting sum and count using ArcPy?

I am having some trouble creating a new shapefile and CSV to group wildfires into seasons. What I want to do is to group the wildfires by meteorological season (summer, fall, winter and spring) for ...
1
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1answer
90 views

Calculating skewness and kurtosis with command line GDAL?

I have calculated histogram bins with the -hist option in gdalinfo. Is there an option to calculate skewness and kurtosis, using this or any other GDAL tool?

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