Questions tagged [statistics]

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

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8 views

How do I generate tiffs with complete (i.e. not approximate) statistics?

thank you for your help. I have tiffs of environmental variables (e.g. temperature, depth etc.) that have continuous data. I only need values within the raster that geographically fall over the ocean, ...
0 votes
0 answers
11 views

Statistical Diagram in Classification dialog box not showing/working

I am using ArcMap 10.5, and for some reason in any kind of raster I use (or point shapefile), when in properties->symbology->classified->classify, the statistical diagram in the ...
2 votes
1 answer
49 views

Calculate percentage of points within land cover classes QGIS

I am working on a project for my university and this is my first solo project. I have a land cover classification with 6 classes. I also have a set of points that are recorded sightings of a mammal we ...
2 votes
1 answer
34 views

Seeking faster alternative to arcpy.Statistics_analysis?

I'm using arcpy.Statistics_analysis to count records and it takes about 30/35min for a table with about 6.8 million records, in a bigger script, this is a big chunk of the whole time. The result of ...
0 votes
2 answers
42 views

How to use ArcPy SearchCursor, with a where clause, to return string formatted response with values

I am using an ArcPy Search Cursor to return the rows of a specified field within a shapefile. The for loop iterates through the feature class and returns the value of the rows in a formatted string as ...
2 votes
0 answers
27 views

Statistical summary of points in a polygon (QGIS)

Is there any method for calculating the average, largest value, etc. (chosen statistic value) of points within polygons and giving the calculated value to the polygon?
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28 views

Getting percentage of parcels covered by slope polygon file using ArcGIS Pro without using Identity?

I've read the other similar stack questions and they weren't helpful, as in the processes didn't work or there was some ambiguous field references that may have contributed to my confusion and error. ...
2 votes
1 answer
62 views

Dynamic stats in the decoration title lable, by time stamp, in QGIS

I am trying to create a visualisation method of simple stats using the title label in QGIS canvas. I need to observe temporal changes in the stats, so I have tried to specify a dynamic chunk of text ...
0 votes
0 answers
50 views

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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0 answers
25 views

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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1 vote
0 answers
95 views

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, ...
2 votes
0 answers
73 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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2 votes
2 answers
84 views

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 ...
0 votes
1 answer
98 views

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 ...
1 vote
2 answers
136 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 ...
1 vote
1 answer
135 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 ...
0 votes
1 answer
101 views

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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0 votes
1 answer
61 views

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 vote
1 answer
83 views

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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1 vote
1 answer
109 views

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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0 votes
0 answers
27 views

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 ...
0 votes
1 answer
28 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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0 votes
1 answer
506 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....
1 vote
0 answers
80 views

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 ...
0 votes
0 answers
30 views

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. ...
0 votes
0 answers
65 views

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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45 views

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 ...
0 votes
3 answers
56 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. ...
7 votes
2 answers
527 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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1 vote
0 answers
58 views

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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0 votes
1 answer
59 views

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 ...
0 votes
1 answer
245 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 ...
1 vote
0 answers
20 views

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, ...
1 vote
1 answer
605 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 ...
0 votes
1 answer
110 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: ...
0 votes
1 answer
58 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 ...
1 vote
1 answer
357 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 ...
1 vote
0 answers
68 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 ...
1 vote
1 answer
50 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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0 answers
152 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 ...
9 votes
2 answers
345 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 votes
1 answer
60 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, ...
1 vote
2 answers
121 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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0 votes
1 answer
470 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 vote
1 answer
146 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
171 views

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 ...
1 vote
0 answers
44 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
161 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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1 vote
0 answers
31 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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0 votes
0 answers
45 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 &...
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