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

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1answer
24 views

Overview of statistical maps/charts types

I know of a few ways to visualize statistical information on a map, like choropleth maps, prism maps or simply displaying little bar-charts or pie-charts near locations on a map. But there must be a ...
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2answers
26 views

How to add a pie chart based on all (or some) features in a layer?

I have a vector layer in a QGIS project which has about 60 items with various attributes, including a check for if an item is complete. I am trying to get a pie chart showing the percentage of the ...
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1answer
24 views

Calculations from Feature Server and display values

Using the ESRI JS API I would like to apply some basic math based on the Shape.area of a feature and then return that calculation to the web-page. I can't see any reference to something even remotely ...
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1answer
44 views

How to create a x-y scatterplot from attributes in QGIS 2.0?

There are a few old packages that allow the creation of x-y scatter plots from attributes in vector data (Scattergram for 1.7) http://plugins.qgis.org/plugins/scattergrammidentify/ (SPQR for very ...
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1answer
86 views

What do “count”, “mean”, and “sum” in QgsZonalStatistics mean?

I am working with Qgis and making some analytics of lightdata. I've used these commands: rasterfile = qgis.utils.iface.mapCanvas().currentLayer().source() vectorlayer = ...
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0answers
34 views

Why does it take so long to run zonal statistics?

QGIS 2.0 Windows 7 I have pulled agricultural data from NASS CDL in tiff format. I want to track where a certain crop has grown over the years. My intention was to use a county shapefile overlaid ...
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0answers
16 views

Cell Statistics in QGIS

Cell Statistics in ArcGIS will calculate the mean (or statistic of choice) among multiple rasters on a cell-by-call basis. Can QGIS do this? If so, how?
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3answers
104 views

Select layer by attribute: return top 3 records

I have a feature class in a file geodatabase using ArcGIS 10.1. I want to create a model that selects the three features with the highest values in one field (Average Price). Basically I want my ...
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0answers
37 views

Bivariate Mapping (running a single variable regression and mapping r-squared value)

I am hoping to produce a bivariate map displaying the correlation between two variables (specifically percent SNAP participation by county against several social variables). I would like to produce ...
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0answers
33 views

Statistically compare two density maps?

I (will) have a modelled distribution and an observed distribution of animals. If I were to interpolate these position datasets to reflect some density distribution (perhaps using a kriging ...
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0answers
44 views

Calculate ANOVA using GIS

It's possible to calculate a statistic like ANOVA using GIS. I'm using ArcGis, but there's any GIS software to calculate it? Thanks,
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0answers
25 views

How to export raster into ascii without losing the statistics?

I had a problem in Mike Urban with a difference between a DEM (Digital Elevation Model) and a 2D overflood model and the support group requested me to remove the difference because the problems were ...
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0answers
27 views

Habitat Modeling and OLS Regression [closed]

I’m performing some habitat modeling for a certain species using resource selection functions to determine optimal variables for including as model parameters. I am using OLS within ArcGIS for the ...
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0answers
30 views

Zonal statistics returns wrong values in QGIS

I used zonal statistics for a simple task: to transmit raster pixel values to vectormap which contains squares as big as the pixel size is. The problem is that the values of the outcome are not ...
2
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1answer
106 views

GIS Analysis - best way to combine and display demographic data?

I am currently undertaking a demographic research project for my employer. We have the data on income, age, sex, language, transport etc and I have mapped most of it and created some thematics of said ...
0
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1answer
29 views

Creating quintiles in QGIS when the number of observations per row is variable

I have a list of 100s of schools (1 per row), and a variable column with the total students in each school. The number of total students in each school varies widely. I want to split the list of ...
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2answers
66 views

How do simple statistics based on polygons?

Hi I have a shapefile from a city. I divided this shapefile into polygons (squares, majority). I would like to perform simple statistics in each square in a easy way, because it is almost impossible ...
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1answer
31 views

How to use the local macro to do ZonalStatisticsAsTable in batch

I have a series of files named as 'rawfile200101', 'rawfiles200102',...,'rawfile201104'. I want to do ZonalStatisticsAsTable for each of them with names corresponding to the time of the raw files, ...
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1answer
50 views

How to calculate statistics for several subcatchments (polygons) in the same time? [duplicate]

I have a shapefile of groundwater management zone which is composed of 40 subcatchments (40 polygons). I'd like to calculate the max., min. and mean elevation for each subcatchment. Would you please ...
0
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1answer
48 views

How do I get basic statistics on a field in a joined table?

I have a shapefile to which I've joined a table, matching with an ID field. All the fields of the table show up correctly when I open the shapefile's attribute table. But when I go into ...
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1answer
18 views

How to Compress/Stack Landscape features to examine spatial distribution and fragmentation?

I was wondering if anyone could help me figure out how to compress landscape information from multiple rasters (or polygons) into a single output. Basically, I want to explore how landscape ...
1
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2answers
219 views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
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0answers
44 views

Mann-Whitney U test for rasters

I'm doing a Mann-Whitney U test to compare two very large samples (sample size 1 = 13250; samlple size 2 = 38871) originating from a shapefile with 52121 features. I know t-tests are not recommended ...
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0answers
30 views

resampled thematic map accuracy

I've generated a map of ecoregions based on some environmental data using a semi-supervised classification where I combined a statistical clustering with random forests to generate my map. I created ...
3
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1answer
88 views

How to create Series of Rasters that displays Standard Deviation from Mean?

Cell statistics question for you. I have 100 rasters of raw rainfall data in which the pixels each represent rainfall for that particular pixel on the landscape for a single year during the 100 year ...
2
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0answers
28 views

Is there a way to find the closest anticorrelated polygon or automate what is learned in the semivariogram?

I am trying to do spatial autocorrelation of sorts based on a layer of polygons of mean rainfall data. I want to see how rainfall deviates from a certain point on the landscape. Essentially, I want to ...
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1answer
256 views

How to call processing toolbox in Qgis' python console

I have been trying to use processing toolbox via python console in Qgis 2.0.1. I am able to write the following comamnds: I am particularly interested to run 'r.statistics' from GRASS module. ...
3
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1answer
163 views

PCA on correlation matrix in ArcGIS

I am trying to run a PCA on a set of normalized raster bands within ArcGIS. I would like to calculate the PCA on the correlation, not the covariance, matrix of the PCA, but Arc as far as I can tell ...
0
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1answer
95 views

How to perform GRASS v.rast.stats via QGIS

I have been using qgis for the last few months. I got interested in using GRASS tools through QGIS. I wanted to compute zonal statistics for a raster surface for a given polygon layer. I loaded the ...
3
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1answer
140 views

How to sum up all field values in QGIS modeler

I am building a model to generate two zones around a point, a 250m-buffer, and a ring of 250 to 1000m, where i recalculate values from an other layer according to the intersections share. The purpose ...
5
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2answers
119 views

Different models, different contours: are they comparable?

I will get contour lines of electromagnetic field strength around power lines. The contours will be calculated by different agencies using different models. We need to check whether the resulting ...
2
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3answers
220 views

How to count occurrences of one field grouped by values of another?

Is there a way of calculating the number of unique text strings in a field in ArcGIS 10.1? I have a number of repeated strings in this field, but would like to calculate the number of unique strings ...
2
votes
1answer
371 views

What is the difference between nominal, categorical, ordinal, interval and ratio measurements?

Given the following examples, which are examples of nominal, categorical, ordinal, interval or ratio measurements? bushels of wheat per county vegetation type average maximum daily temperature ...
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1answer
251 views

identify percentage of raster cells within a polygon

As per the title I want to determine the population inside multiple polygons according to different land use zoning (High Residential, Low Residential, National Parks etc) that's in raster format. ...
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1answer
100 views

Retrieving the proportion of specific pixel class from CHM rasters

CHM = canopy height model I am very new to R (specially for GIS purposes) and I am struggling a bit in getting the following pixel statistics: Proportion of zero value pixels = [nº of zero value ...
0
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1answer
243 views

How to calculate median value of polygon from points in ArcGIS?

I have a point layer coming from LIDAR data containing x,y,z and intensity values. On the other hand I have a layer containing several polygons. All the points are inside the polygons. I need to ...
4
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0answers
220 views

QGis Zonal Statistics Plugin NoData included in Calculations

I have been trying to use the QGIS zonal statistics plugin. My raster has a nodata value of -99999 and all other values are positive. After computing the mean zonal statistics there are a number of ...
3
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1answer
77 views

Sensitivity analysis for coarse scale GIS epidemiological model?

I am working on an epidemiological model with disease incidence rate as dependent variable and environmental factors as independent variable. Disease data is available at county scale whereas ...
1
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1answer
118 views

Sum of point attributes inside hexagons using QgiS UI

I'm very new to Qgis so I would very much appreciate any help you can give me. I have a point shapefile that corresponds to locations of animals captured. I've joined a table to this shapefile with ...
2
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2answers
180 views

Looking for ArcPy tool for calculating statistics on field with summary field AND boolean fields

What I'm searching for is a tool that will sum a field by a secondary unique field AND booleans... Let's say I have 12 table each with 4mil records and the following fields: Donation_Amount ($ ...
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3answers
37 views

Europe sub-national urban rates

Urban rate (the % of population living in urban areas) is a rather common demographic indicator, at nation-level resolution. I'm trying to locate sub-national urban rate data (NUTS level 2 to be ...
3
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0answers
78 views

Why are my raster mean and standard deviation -1?

I have a set of about 25 rasters whose descriptive statistics I have been examining. The data in the rasters were calculated in Python and the rasters were created using Python-GDAL. In all but one ...
0
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1answer
70 views

QGIS create point data attribute as the name of the polygon it falls in

I'm working in QGIS with a point data set overlaying a farm with 140 fields. While I can analyse the points from each field individually, I would rather use an awk script to calculate statistics I ...
8
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2answers
164 views

spatial and spatiotemporal analyses

I have a dataset that consists of 247 mosquito traps placed in fixed positions and sampled weekly for 23 weeks. I also have dengue disease incidence data (indexed to home address) during the same time ...
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0answers
58 views

Reshape Matrix and perform Zonal Statistics in Matlab

I have 2 grids: 1) n by m - at 100m 2) n*10 by m *10 - at 10m. These grids cover the same area. I have to perform zonal statistics at scale of grid no.2. Cell value of grid no.1 is cumulative for ...
4
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0answers
154 views

How to analyse correlations between variables and points? [closed]

I have just lost the past 8 hours on this, and literally getting nowhere - hoping someone can help before I go mad! I am trying to determine the correlation between sinkholes and a number of ...
1
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0answers
49 views

How to join two fields after calculating ?

I have been working with two layers and I am trying to join them and turn them into a raster data. The first layer is a watershed layer which I have assigned each shed a location from the center point ...
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0answers
261 views

QGis Grid statistics for polygons error - Module caused access violation!

I'm trying to calculate statistics for a raster layer using an overlaying polygon layer, I'm using SAGA "Grid Statistics for polygons" function, but it returns an error, sadly.. So in the sextante log ...
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0answers
56 views

Area statistics in Qgis

I just want your help to summarize areas in two levels; firs level is in a field (Municipalities) and in other field I have Has and finally a third field "values" that came from a raster, the values ...
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0answers
41 views

basic statistics in qgis lisboa doesn't work under shapefile

When I add csv file and the basic statistics works well, after I save it as shapefile, and the basic statistics doesn't work properly under shapefile, why?