Questions tagged [statistics]
Collecting and analyzing numerical data or making numerical summaries of data.
336
questions
5
votes
1answer
48 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 ...
1
vote
0answers
8 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
votes
1answer
33 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
votes
1answer
46 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
votes
1answer
31 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
votes
2answers
33 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
votes
1answer
40 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
vote
1answer
55 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
votes
1answer
52 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
votes
1answer
60 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
votes
1answer
25 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 ...
1
vote
0answers
33 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
votes
1answer
76 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
votes
0answers
36 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
votes
1answer
83 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
vote
1answer
52 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
votes
0answers
18 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
votes
1answer
40 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
votes
0answers
23 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
vote
1answer
90 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 ...
0
votes
0answers
71 views
Converting distance from km to degrees (WGS84)?
Is there an equation in which I can convert distance in kilometers into degrees?
I am performing a Kriging analysis and when I am measuring the distance between the input points (for LAG and Major ...
1
vote
1answer
55 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?
0
votes
0answers
47 views
Image Statistics Import in Google Earth Engine?
I've wrote this code for Nitrogen Index. but it returns error. how can I solved this?
code link: https://code.earthengine.google.com/ff6954984a933d11580d2717ba59670e
error massage:
Layer 2: Layer ...
4
votes
1answer
53 views
Using lidR to count number of pulse returns at different intervals?
I am trying to get the number of pulse at different height interval.
I have used the lidR package to do this before with the code below but it seems that recent update in the package breaks my code. ...
2
votes
1answer
73 views
Zonal statistics basic output
I have been using the zonal statistics tool to quantify the variability of slopes around archaeological sites.
I have noticed in some experiments that there are differences between the mean and the ...
0
votes
2answers
38 views
Standard deviation or standard error, which is right to present along with average as error bar?
I have monthly sea surface temperature data set for 1 year.
I need to present seasonal average as bar chart and error bar to show deviation in each season.
for example,
season 1 = nov+dec+jan+feb/4
...
0
votes
0answers
43 views
Comparing two spatial point processes (Cross K Function)
Suppose we have two spatial point process on the same space. One has $n_1$ points, the other $n_2$ points.
I have been reading about statistically testing for independence, attraction or repulsion ...
0
votes
1answer
43 views
Create mean raster stack from raster stack
I am trying to create a mean stack image(1 panchromatic layer) from a stacked tiff image(13 panchromatic layers). How do i go about doing this?
My code:
from osgeo import gdal
import numpy as np
#...
2
votes
1answer
147 views
Calculating Length of Lines within polygon (buffered area) using QGIS?
I created a buffer around points and then merged these buffers to eliminate overlaps. Now I want to calculate the exact length of tracks within this area. It might be the case that at some points the ...
0
votes
0answers
27 views
Why the Masking in ENVI does not give different statistical result
I want to run statistical band correlation of an image in ENVI. The image has been masked with polygon of interest, and shows no-data value outside the polygon. I expected that it calculated only the ...
1
vote
0answers
28 views
Summing Attributes based on ID Field using ArcGIS Desktop?
I'm trying to sum attributes based on if their ID matches the ID of other attributes in the feature class. To explain further, each road has it's own Replacement Cost and Section Number as well as a ...
2
votes
0answers
53 views
Calculating share of overlapping areas via aggregate function in a virtual field
I'm trying to calculate the shared area for several overlapping areas. I need a dynamic solution in order to get automatically calculated statistics when drawing new polygons.
The target area is in ...
0
votes
0answers
13 views
QGIS Group Stats - no option to add columns showing “first” value
I have a bunch of lines that have a phase name, and then a type. So like "Phase 1" and "12in Water". I have many phases and types in this dataset, and want to list the items in each phase, and the ...
1
vote
2answers
64 views
Calculate raster statistics for polygons in a polygon feature class
I have a DEM across my study area where symbology has been changed to show elevation changes in 100m intervals.
I have a polygon feature class where each polygon delineates a landslide.
My landslide ...
1
vote
1answer
149 views
Calculating incoming net radiation using Google Earth Engine?
I am a beginner with GEE and I am trying to calculate the incoming net radiation for that I need the square inverse of relative earth sun distance using the expression dr = 1 + 0.033*cos(J*2*pi/365) ...
0
votes
0answers
27 views
Statistic validation for spectral trajectories/trend from ground truth dataset
I'm doing an extraction of spectral trajectories for disturbed forest pixels using multitemporal (single scene for 20 years) Landsat Surface Reflectance products.
Usually, forest disturbances are ...
0
votes
1answer
54 views
Counting attribute value based on location using ArcGIS Pro?
I have a school district polygon divided up by neighborhood, and I am trying to determine the number of students from each grade per neighborhood. The student point file contains an attribute with ...
1
vote
2answers
190 views
Calculate the percentage of a Line passing through Polygons
I have a polygon layer of a region (100% coverage, no overlaps) and a line layer in the same region.
I want to calculate for each line to which percentage it crosses certain polygons.
I have seen ...
1
vote
1answer
76 views
Classifying fields and getting statistics in ArcMap? [duplicate]
I am using ArcMap 10.6.
I have a table with country data. I am interested in Asia only, so I created a new layer (and shapefile). Several countries have missing data, which was filled with the same ...
0
votes
1answer
31 views
Comparing multiple means in ArcMap?
I have two fields of LU_Name and BETW.
Is there any tool which compares the means of BETW in different groups based on the LU_Name nominal field and reports their significant correlation?
0
votes
0answers
24 views
ERROR in R - it cannot support the vector
I did use the function crop and mean for 434 rasters in Rstudio. Each one is very big, it corresponds almost like 1/4 of Brazil.
Now I want to calculate the standard deviation between these 434 ...
0
votes
1answer
50 views
Maximum Value Within Area
I have a large set of points and need to determine the individual point with the maximum value for a given attribute within 12 km quadrants and extract these to a separate shp. Currently, I have ...
-3
votes
2answers
32 views
Get stats from a shape inside another shape
I have a big shapefile with many features.
Then I have a another shape of less size, wich is in the same space that the first shape.
I need to get stats (area, %) from the first shape that only match ...
0
votes
0answers
88 views
Calculate Bare Soil Line Intercept using R
I am using an R package called BSL (Bare soil line), package is at https://rdrr.io/cran/landsat/man/BSL.html. The BSL package uses R's lmodel2 function (https://cran.r-project.org/web/packages/lmodel2/...
1
vote
1answer
259 views
Using Statistics by category in QGIS?
I use the "statistics by category" tool from QGIS to learn what grain yields I got from different combinations of scenarios like:
Soil A + Hybrid A + Planting Date A = Yield n
Soil B + Hybrid A + ...
0
votes
0answers
56 views
R circular statistics on a raster time series
I have a raster time-series with values from 1 to 36 representing 10 days (dekads) timesteps and NA values.
I need to calculate the average and the standard deviation, taking into account that ...
-1
votes
1answer
58 views
Sum attributes of feature that occurs multiple times within a layer
I am trying to add up the total contributing drainage area of multiple stormwater BMP's that are located on the same parcel for a layer that contains tens of thousands of parcels. I performed a one-to-...
1
vote
1answer
392 views
Differences between Operations Dashboard for ArcGIS and Power BI? [closed]
We are looking for a possibilty to show some live statistics and calculation over geodata (the developement on some retail markets ) and want to see what is suitable. I have tried Power BI and have ...
0
votes
0answers
46 views
Parameters for BSL Package in R
I am using the landsat BSL (Bare Soil Line) package from R https://rdrr.io/cran/landsat/man/BSL.html, and I am wondering why the code sample is using llimit 0.005 and not 0.01:
BSL(band3, band4, ...
1
vote
1answer
141 views
Calculating Bare Soil Line using R?
I am using a package in R called BSL (Bare soil line), package is at https://rdrr.io/cran/landsat/man/BSL.html. I've used it successfully to run regression line for my soil study area but it is ...
