Questions tagged [statistics]

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

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1answer
599 views

Graphic output for Ripleys K function

I am using ArcGIS to calculate Ripleys K function using the "Multi-Distance Spatial Cluster Analysis (Ripleys K Function)" tool on a point feature class. I can see a table output but want a graphical ...
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1answer
194 views

How to work with Spatial Autocorrelation (Morans I) on equal weighted point

I have a point feature class. All points are the same, it's not weighted. I want to use Spatial Autocorrelation (Morans I) tool but it only takes a field for weight. I tried fooling it by adding a ...
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3answers
671 views

How do I calculate average in my field calculator within specified limit?

I would like to calculate the average, max and min of each trips that I have. Each trips are also predefined (e.g. Trip 1, Trip 2) in the attribute table. (As below). I have more than 2000 trips. ...
3
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1answer
2k views

Calculating summary statistics and access resulting value in table using ArcPy?

With arcpy, I want to calculate the mean value of a specific field in a shapefile and print the resulting value for the user. I use the Summary Statistics tool and it works, but the resulting value ...
3
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1answer
447 views

Table of statistics of rasters input in QGIS

I work with QGIS GDAL,I have many raster image 'geotiff' with one band for many dates, I want to create a table that contains statistics for all rasters that I have. I tried the algorithm 'raster ...
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1answer
91 views

Correlating raster layers

I am trying to correlate contaminant data with other variables. For instance I want to see if high values of contamination coincide with topographic lows in my elevation raster (DEM). All the layers ...
5
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2answers
1k views

Retrieving LiDAR metrics from relative vertical layers of point cloud?

I need to obtain the proportion of all returns within 5 equally spaced height bins between the cutoff (1 meter) and the maximum height value. I need to get this proportion of all returns for 1000 ...
1
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1answer
831 views

Identify the top 10% of raster cells

I have a raster with different risk values for a hazard. How can I identify the top x% (eg. 10%) of the raster cells with the highest values within ArcGIS?
1
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1answer
53 views

Replace Statistics_analysis with SearchCursor?

I'm using ArcGIS 10.3, 64bit with an advanced license. I have the following code, that runs just fine. It goes through a table that contains a large number of entries with zip-codes and population ...
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2answers
672 views

How to automatically sum up values within buffers?

I want to establish the population figures within multi-ring buffers around certain site. I have set up the buffers and am running a select by location query on each concentric ring. Once the ...
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1answer
755 views

How to perform statistical test for two sets of points?

(I have asked this question originally on Cross Validated; however, no good answer and someone suggested me to ask the question here). We know that we can perform statistical test (e.g., t-test) for ...
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2answers
74 views

More information from Summary statistics tool in ArcGIS

I try to find the MAX value for every distinct element in a dataset (I done this using MAX in summary statistics) but I also want to have the id of the element corresponding of that MAX in my output ...
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1answer
297 views

Calculate the frequency of classes of neighbouring raster cells

I'm struggling with a problem when working with a raster dataset of biotope types: For each cell I would like to find out the frequency of classes in the adjacent cells, e.g. from the 8 neighbouring ...
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1answer
86 views

Performing Statistics operation on field in Attribute table?

I am working with the Shapefile consisting set of points. One of its field (let's call it X) contains numeric data, ranging from 0 to 1. In order to find out the average value of field X, I opened ...
3
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2answers
486 views

Passing in complex parameters to geoprocessing tool?

I'm currently using the Statistics geoprocessing tool (called Summary Statistics in the UI) from ArcObjects. This tool accepts two "complex" (for lack of a better term) arguments: Case fields ...
3
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1answer
442 views

Extracting NDVI using QGIS from multiple images to Excel?

I created 25 images in QGIS. Each image has different information about the NDVI of the area. How can I extract mean, max, and min information about the NDVI from each image and put it in Excel?
1
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1answer
87 views

extracting statistics from a raster within the extent of a polygon

I have a polygon representing the extent of a study area. This polygon is overlaid to a raster representing the quality of land, which is classified into 5 classes (from bad [1] to good [5]). I would ...
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0answers
100 views

Statistically comparing surface slope of 2 different areas? [closed]

I could use the statistical tests like t-test and ANOVA, however I am afraid those test will easily show significant differences if I use the slope values of all cells from each area.
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2answers
3k views

how to get max and min from a raster using arcpy?

I have a land surface temperature raster file and I want the max and min of it. minLSTresult = arcpy.GetRasterProperties_management(raster_result, "MINIMUM") minLST = minLSTresult.getOutput(0) ...
3
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1answer
2k views

Finding Median, Max and Min values from Raster Layers in QGIS

I currently have 10 years worth of January raster datasets (working on just one month at the moment) of cloud fraction cover from MODIS, and am trying to create new 3 separate rasters which will give ...
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2answers
247 views

Error Trying to Run R Summary Statistics in QGIS 2.12.1

When I try to run the R script "Summary statistics" in QGIS 2.12.1 on a Windows 7/64 bit machine, I get the error message "error in if (!file.info(DSN)$isdir) DSN missing value where TRUE/FALSE needed,...
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1answer
1k views

Calculate percentages with field calculator in arcgis?

I am trying to calculate the percentage of each the area of each polygon in the selected area. I tried using ( math.fsum(!shape.area!) / !PolygonArea! )*100 and other codes but I cannot make it work. ...
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1answer
415 views

Cell Statistics failing to read rasters in list

Heyo. I'm trying to get the rasters from a list (about 32 rasters) and then sum them up with CellStatistics in arcpy. I'm using Python 2.7.8 and ArcGIS 10.3.1 I got it to work the first time around ...
10
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1answer
5k views

Calculating spatial correlation between features from two separate layers in QGIS

I am trying to determine whether the presence of large numbers of active duty military troops in an area is spatially correlated with higher/lower levels of violent crime. That is, are the areas ...
2
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1answer
182 views

Resampling gives higher MEAN when using zonal statistics

I am using ArcGIS 10.1 for Desktop. I have a value raster and a polygon feature in GCS coordinates. My raster resolution is 0.5 decimal degrees which is much larger than the size of my polygons. My ...
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0answers
305 views

Explaining different results from Ordinary Kriging and Universal Kriging?

When using either methods to create a surface from the same set of observations, these surfaces differ from each other. Visually it can be seen in the differences of the following contours (...
3
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2answers
1k views

Generating DEMs from point clouds and differencing them?

I have two point clouds obtained via structure from motion (ground photos of sand-dunes + Visual SfM/Agisoft Photoscan). If I wanted to generate a DEM from these point clouds and difference them to ...
2
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1answer
283 views

How to separate out bands from hyperspectral data using R

I'm having one hyperspctral data with 426 bands, with dim 250*250*426. I want to seperate each bands. I tried like this img <- stack("name.tif") rr <- array(, dim= c(250,250,426)) for(i in 1:...
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3answers
249 views

How to show statistically significant incident locations

First let me preface with I tried to search for this solution first but I don't really know how to word it and could not find any results so excuse me if this is a duplicate. I would like to know how ...
1
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0answers
39 views

Statistical bias arising out of only comparing US census block groups that have not changed (been split) over time?

Census Block Group ("CBG") study areas are notorious for changing over time. Even from 2009 to 2013, about 10-25% of the CBG's in South Carolina have not remained consistent over that time. Seeing ...
26
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3answers
4k views

Major bug in ArcGIS Zonal statistics?

Update: The bug has been fixed in the ArcGIS 10.4 release I am using ArcGIS 10.2.2 to determine zonal statistics for a number of zones. If there is any NoData in the value raster, I want the zone ...
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0answers
121 views

Raster Area within a Polygon

using ArcGIS, I have a layer of overlapping polygons and a raster grid underneath. The raster is not a continuous grid - the cells are spread out. I simply need to calculate the total area of the ...
5
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1answer
349 views

Index express the similarity in shape between two data sets

I have two data sets. One is points in the blue curve. The other is points in the green curve. Now I want to find a property (P) or something else like index that has the following characteristics: ...
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0answers
742 views

Invalid drop item: Calculate statistics

I have a number of rasters that I need to calculate histograms for. These are continuous rasters from 0 to 294.208 - many decimal places. I need to be able to classify the histogram down to at least ...
4
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2answers
4k views

How to sum pixel values of a floating point raster in ArcMap?

I have a floating point raster with values from 60 up to 95 (with decimals), it has 7077 pixels of 250x250m size. Is there a way to sum all pixel values of this raster? For example, if the raster had ...
0
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1answer
341 views

Where can I find geodata for the Russian терсон-мо or терсон-ате census units? Or: can osm_admin polygons be linked to those?

I'm looking to combine Russian census data with georeferenced polygons. This is for a research project looking into different aspects of mobility within the Republic of Саха (Sakha/Yakutsk), the ...
2
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0answers
180 views

Zonal statistics error: 0-d arrays can't be indexed

How can I fix the error 0-d arrays can't be indexed? This message appears after the tentative to use the algorithm Qgis Zonal Statistics. Detail: the algorithm worked very well several times and then ...
2
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1answer
105 views

How to get the upstream average of a raster data layer that falls into a river network?

I have a raster layer of a network of rivers and a raster layer of data I want to extract. For each pixel of the rivers, I need to know the upstream average of the data layer that falls into the ...
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1answer
1k views

How do I Calculate Grouped Percentiles or Batch percentiles in ArcMap?

My question is similar to this one which was answered successfully: Calculating Percentiles in ArcMap? My addition is how do I batch this solution for multiple files or apply a group-by feature to ...
2
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0answers
156 views

Some output cells show up as noData in ArcMap Block Statistics? [closed]

I am using ArcMap 10.2.2, and I need to aggregate categorical data from 30m up to 90m and 900m resolution for species distribution modeling. The algorithms available in resample (nearest neighbor, ...
4
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1answer
6k views

Calculating raster statistics for each band in QGIS?

i need to calculate raster statistics for RGBN (4 channels, multiband image) rasters in QGIS. In Arcgis if you use "calculate statistics" in ArcCatalog, statistics are calculated for every image ...
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1answer
216 views

Counting points in concentric circle buffer zones of different sites in a map? [closed]

I produce concentric circles of 200 and 500 m buffer zones to see water points within each buffer zones. The buffer zones are created throughout my study area. How can I count the points found in ...
2
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1answer
545 views

Accessing bands in .pix (PCIDSK) file in python/arcpy

I am trying to perform zonal statistics on a single band from a multi-band raster in .pix format. I have things working great with a tiff file. I am able to access the bands using this code: desc = ...
0
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1answer
1k views

Zonal Statistics as Table output is missing some polygons ONLY when run from Python script

I have a raster file from which I am attempting to calculate mean values for polygons defined in a shapefile. Using the Zonal Statistics as Table tool from within ArcGIS works great. My shapefile ...
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1answer
1k views

Unit of measurement from standard error prediction map?

I am performing an ordinary kriging analysis and came out with the prediction standard error map. I would like to know the units of such map. Can anyone help?
2
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1answer
3k views

How to calculate RMSE of geographic coordinates?

I've been working on my project and I stumble upon how I can calculate the Root Mean Square Error (RMSE) of geographic coordinates. What I have is a derived coordinates from processing LiDAR data ...
0
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1answer
30 views

Need statistics from US census [closed]

I am not sure if this is the right place to ask, if so please recommend a stackexchange, I am having a lot of issues getting the data approximations that I need for a report. I am looking for the ...
1
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1answer
2k views

Extract values from raster by using polygons

I am working with multiple raster files that cover all of united states. The file format of the rasters - GeoTIFF. I have around 100 geotiffs that I need to process. Then I have another shapefile with ...
2
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1answer
317 views

QGIS equivalent to MapInfo Sum Attributes for selected vector objects?

I´m looking for QGIS equivalent to the basic MapInfo tool "Sum Attributes". I´ll explain what it does: For selected objects in a vector layer, a popup window shows basic statistics such as: - Sum ...
1
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1answer
77 views

Can I no longer see my view counts in the new dashboard?

The inset graphic shows the relative up and down of each day's views, but I can't see any numbers. I'd love to continue tracking my monthly stats.

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