Tagged Questions

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

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2
votes
1answer
35 views

How to make zonal statistics model more efficient?

I've made this model, to assess some 500-600 rasters for one area, and spit out one huge table. So far, when testing it with 20-30 rasters as inputs it works, but now that I put in the full amount its ...
3
votes
1answer
23 views

raster statistics by line shape (vector)

I have a georeferenced area where I created 7 raster maps (classified with suitability values from 1 to 5) as I have 7 factors to check e.g. natural reserves, floods, slopes etc. From there I did a ...
3
votes
1answer
57 views

How to get counts from a table to produce a heatmap?

I am trying to create a heat map of doctors per zip code based on zip code. I have a table with the doctors and their zip codes, some of them repeating because there is more than one doctor per zip ...
1
vote
3answers
23 views

Raster statistics

In ArcMap, I have a raster layer representing site locations. I derived elevations values for the sites from a DEM. Now want stats on distribution of elevation values at those sites. How can I do ...
0
votes
3answers
30 views

Capabilities of the Analytical Hierarchy Process (AHP) in conjunction with the weighted overlay tool

I am making a prospective map of fossil deposits using the "Weighted Overlay" ArcGIS tool. Input factor rasters are mostly topographic in nature (elevation, roughness, TPI, etc). Initially, I had ...
1
vote
1answer
19 views

Two maps, one with classes and one with no classes. get the sum of one map into the classes of the other

I have two maps. One map has some classes and the other one is a raster with no classes. To illustrate, the map with the classes: 0-1, 1-2 and 3-4! The other map is a raster with values from 0-1000. ...
1
vote
0answers
27 views

Plotting N-S and E-W Profile of Land Surface Temperature (LST) Across Land Use types in ArcGIS for Desktop?

I am working on my final year thesis and I need to plot the seasonal North-South and East-West profile of land surface temperature (LST) across various land use types. I have been able to extract ...
1
vote
1answer
24 views

Why am I getting small float numbers when aggregating points containing large integer values in QGIS?

I have a layer of points containing the centroids of European NUTS regions at NUTS 3, with population data in the atttribute table. I want to aggregate this population data to NUTS level 1, which is ...
0
votes
1answer
55 views

arcpy SearchCursor return a OBJECTID value not as an integer

I use summary statistics GP tool to extract the max OBJECTID from a feature layer. After that I use arcpy SerachCursor to get the OBJECTID value from the statistics, but the result returned is not an ...
1
vote
0answers
10 views

Calculation of RMS between two grids [duplicate]

I want to calculate the RMSE of two grids based on their z-value: a calculated and a reference grid. I do have the statistics: Cells, Range, Min, Max, Sum, Mean, Variance, St.dev. How could I solve ...
2
votes
0answers
68 views

How do I statistically compare positions from two track datasets?

I have two datasets with positions that I need to compare. One would be the "observed" positions (someone took the GPS positions manually) and the other one was calculated using a software. To use ...
4
votes
1answer
113 views

Why covariance values are different in R and ArcGIS?

I've calculated covariance between 7 rasters using R and ArcGIS. It gives me different results. Each times covariance values from R are approximately 1.874 times higher than ArcGIS values. R - ...
2
votes
2answers
137 views

Zonal statistics for millions of overlapping polygons

I am running ArcGIS 10.1 with 64-bit GP on Windows 8.1 x64. I want to calculate the zonal statistics of buffer polygons based on parcels and a kernel density raster. The 4.7 million polygons overlap ...
2
votes
1answer
40 views

Intersect shapefile with raster, then determine proportion of each raster value?

Using the arcpy module in Python, I want to find the proportion of each pixel value within the boundary of an overlaying polygon. (The polygon is in a shapefile.) For example, there are 10 possible ...
5
votes
3answers
104 views

Is it possible to calculate statistics across multiple fields in arcpy?

The summary statistics command can be used in arcpy to calculate statistics - this tool runs against a single field, eg: SUM—Adds the total value for the specified field. Is there an ...
3
votes
2answers
85 views

How are kappa and overall accuracy related with respect to thematic raster data?

I recently calculated kappa (using confusionMatrix{caret} in R) between a thematic raster dataset at 1m spatial resolution and another at 30m spatial resolution. I was interested in quantifying the ...
6
votes
1answer
81 views

Graphically depict statistical difference between thematic rasters

The graph shows a regression between two raster datasets with classified tree canopy cover: class 1 = 0-10%, class 2 = 10 - 20% ...class 6 = >60% (Figure 1, Figure 2). The spatial resolution for ...
0
votes
1answer
44 views

How I can sum 360 raster files in a folder with the Arcgis raster calculator?

In a folder I have 360 precipitation raster files and I want to sum them all to the raster calculator
3
votes
1answer
57 views

Statistical Analysis of Shapefile Proximity within Raster Image - ArcMap10.1

I have a raster image that has been reclassified into 15 equally incremented values/levels. This raster represents "sinkhole risk" in a certain county. So level 1 is the lowest risk region and level ...
0
votes
0answers
31 views

Zonal statistics vs. random points?

Using ArcGIS 10.1 for Desktop, I wish to model the relation between soil productivity (SP) and a number of independent variables such as, e.g., terrain elevation and slope. For this purpose, I am ...
2
votes
1answer
44 views

Summarizing Table on 2 fields

I have a table of Census Blocks linked to ZIP4 values. I'm trying to create another table getting the unique ZIP4 values associated with each Census Block. I've tried using the Frequency, and Summary ...
0
votes
1answer
31 views

How to implement a Gaussian function in field calculator?

Are there any build-in functions like Gaussian or Epanechnikov functions in field calculator? Or I have to write that by myself?
0
votes
1answer
28 views

Calculating GRID Statstics

I have a GRID raster dataset with no calculated statistics. I have tried building pyramids and calculating statistics with no luck. What am I missing? EDIT: For those who don't understand: 1. ...
0
votes
2answers
107 views

Lengths of lines within individual but overlapping buffers?

I have a set of points for which I have created a 12 mile buffer. Eventually, I would like to know how many kilometers of road exist within each buffer zone individually? The problem I see going ...
1
vote
1answer
53 views

How to derive Z-score values for a given field

I have a shapefile with an attribute field with a range of numerical values. I would like to derive z-score values for this field within ArcGIS. Any tips?
0
votes
1answer
89 views

Counting all features in all layers of ArcGIS map to get grand total?

I have 20-50 polygon layers in an mxd and I want to find out the aggregated amount of all features (global count). The shapefiles which are the source of those layers are stored in different folders. ...
0
votes
3answers
77 views

ArcMap Change Values Greater than Standard Deviation of Mean to Zero

I have a feature class with greater than 1000 features and I would like to change all values greater than 2 Standard Deviations to a Zero. Seems like I could possibly use Field Calculator for ...
2
votes
2answers
73 views

Methods for hot spot or cluster analysis for multiple measurements at the same geographic unit?

I would like to find geographic clusters of zip codes where each zip code has a measurement of a person's age (integer), sex (categorical/binary), and if they recovered from a certain medical ...
0
votes
1answer
139 views

Get the different values assigned to a zip code

I have a map to which I added a zip code layer and another layer which contains values assigned to every square kilometer within each zip code. I'm trying to find out how many different values there ...
1
vote
2answers
103 views

Min - Max within a zip code (statistics by area)

I'm new to ArcGIS. I have created a layer representing zip codes and overlayed it with a layer containing some data points. I want to find the min and max value of the data points in each zip code. ...
0
votes
0answers
80 views

pivot table output

In an attempt to summarise landclasses, the columns of my pivot table output are a bit mixed up with the field info regarding the three input fields that I've selected. As shown in snapshot 3 the ...
0
votes
2answers
59 views

How to track ajax WMS requests in OpenLayers interface?

I'd like to track WMS requests on my openlayers web interface. How is it possible to log on my server or in Google Analytics every WMS requests (GetMap and GetFeatureInfo would be enough)? Then I'd ...
0
votes
0answers
32 views

Performing Mutiple Correspondence Analysis (MCA) using R?

I want to apply MCA (multiple correspondence analysis) to a data table containing regions as individuals, and INFESTED AREA as variable and degree infested also and the type of trees infested , and I ...
0
votes
0answers
31 views

Applying Spatial Clustering test using R? [duplicate]

I’m very new to R so please bear with me: I have a set of area infested by a disease (AIS) annually data and I want to apply some cluster methodology to detect regions with similar (AIS) patterns. I ...
0
votes
0answers
42 views

Sextante and qgis for hotspot analysis

I want to analyze time series data for hotspot analyis. May i know whether sextante and qgis are able to generate any spatial statistics similar to Getis-O-ord in ARCGIS.Or R is required for hotspot ...
0
votes
1answer
127 views

Do I need to run regression in each samples separately?

I'd like to do smooth NDVI image by regression analysis; response of time series NDVI image to Julian date to represent the seasonal changes in NDVI as a function of Julian day. The time series NDVI ...
1
vote
1answer
65 views

How to analyse point data as covariate for areal data

I have two data sets: a) a set of polygons with areal data variables. b) point measures of various co-variates of interest (note I do not necessarily have a point for each polygon) How do I ...
2
votes
1answer
42 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 ...
1
vote
2answers
55 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 ...
1
vote
1answer
52 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 ...
2
votes
1answer
168 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 ...
1
vote
1answer
137 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 = ...
0
votes
0answers
46 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 ...
0
votes
0answers
26 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?
2
votes
3answers
148 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 ...
2
votes
0answers
87 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 ...
1
vote
0answers
55 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 ...
0
votes
0answers
98 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,
1
vote
0answers
43 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 ...
2
votes
0answers
53 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 ...