Tagged Questions

The field of study concerning statistical methods that use space and spatial relationships (such as distance, area, volume, length, height, orientation, centrality and/or other spatial characteristics of data) directly in their mathematical computations.

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2
votes
2answers
305 views

Choosing an aggregation strategy that will be spatially represented on a google map

I'm under an NDA so I cannot really get into specifics of what I am doing. But, suffice to say, I am taking a large amount of spatially-acquired data and drawing this data onto a Google Map surface ...
10
votes
2answers
2k views

Is there a Free Aggregate Points tool out there for ArcGIS 10?

I need to do some Getis-Ord analysis but first I need to aggregate my points. I know of XToolsPro, but the aggregate points function is locked and you must purchase a license to use it. I am ...
6
votes
1answer
389 views

Normalizing and adding kernel density rasters

I have 4 years of road kill data for one road, though each year has a different sample time frame (i.e. May-June vs. April-October) and therefore each year has a different number of surveys and totals ...
7
votes
3answers
1k views

How to cluster points based on a kernel density?

I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
1
vote
3answers
1k views

How to count pixels of a raster in polygons using QGIS?

I need to compute some statistics of the pixels of a given raster that are coincident to the polygons of a vector file. Is there a simple and effective way to do this in Quantum GIS or similar?
6
votes
2answers
4k views

How to do regression analysis between two variables using ArcGIS

I have a temperature image (interpolated from climatic point data) and NDVI data at the monthly interval. I need to do correlation analysis between temp and NDVI. Is it impossible to do this using ...
5
votes
1answer
987 views

QGIS Data Management: How to calculate Standard Deviation?

does anyone know of a way to find the standard deviation of an attribute lying within any given polygon? The plugin dialog "Join Attributes by Location" gives only the options Mean, Min, Max, and Sum. ...
7
votes
5answers
499 views

How to calculate purchasing power on postcode level?

Does anyone know of an algorithm to calculate purchasing power on a postcode level? What source data is needed? Purchasing power on admin. level, population?
8
votes
4answers
1k views

In ArcGIS Is there a tool that will select a percentage (75%) of a whole group of points based on the distance from one separate point?

This is ArcGIS specific. I have 2 point shapefiles A and B, the first one (A) is a single point that contains a lat long, the second (B) is a multitude of points (over 12k) that each contain their ...
1
vote
4answers
4k views

Sum of areas in all each polygon layer?

I've got several layers/feature classes in an ArcMap 10 project. Thanks to everyone's help, I'm able to get the areas for the polygons contained within each layer. By opening the attribute tables ...
4
votes
2answers
741 views

Gaussian Plume Model

I'm looking for code to implement a gaussian plume model in 3D. Any suggestions on where to start? Are there any python scripts out there? Thanks
7
votes
2answers
2k views

Spatial statistics tools : clustering analysis on raster data

I've an apparently simple problem, but i can't find a clear methodology to use. I'm tasked to delimit "urban areas" by vector convex polygons, using the Gridded Population of the World dataset from ...
9
votes
4answers
4k views

How to find Clusters of N Points Within X Distance?

We have tried two methods of cluster analysis: Cluster and Outlier Hot Spot ... but neither meets our specification which has these 3 parameters: a Set of Point features N points within a ...
3
votes
3answers
763 views

How do you produce a output table containing distances between mineral grains at various azimuthal directions?

I am using ArcGIS 10, the newest version and I am a senior at Western Carolina University and working on my senior thesis and the data set in which I have are images of mineral thin sections all ...
1
vote
0answers
675 views

two results of IDW in ArcMAP are different

i added the following points to ArcMAP using "Add XY Data". x,y,z 7,39,117 27,17,122 27,61,123 46,36,136 52,14,138 55,46,141 56,56,137 65,24,144 65,36,145 Changed raster output size in "options" ...
6
votes
4answers
533 views

statistics by rectangle (raster image)

I have a shp file with some rectangles and I want to extract statistics within these areas from a raster image. I prefer ArcMap 9.3.
7
votes
3answers
2k views

Statistical relationships between rasters

I am trying to analyze how sets of rasters relate to each other using some statistical techniques. As, I don't have much experience using the spatial statistics tools in ArcGIS I was exporting my ...
6
votes
1answer
2k views

RMSE between two rasters step-by-step

Can anyone show how to calculate the RMSE (root mean square error) between following two rasters step-by-step and discuss on the obtained results' min and max values, and how to interpret it. Thanks a ...
9
votes
1answer
209 views

Visualization to inference workflow

I provide statistical support for a public health department. As you might imagine, we put together a lot of maps on a regular basis. For me, maps are just another kind of data visualization - ...
25
votes
7answers
4k views

How to compare two spatial point patterns?

If I have two point pattern distributions within the same geographic region, how would I go about visually and quantitatively comparing those two distributions? Also assume I have many points within ...
15
votes
3answers
3k views

Using R with ArcGIS for Desktop (without using GME)? [duplicate]

I am trying to learn R generally and making statistics for maps. I found some useful tricks for making maps with it but it is not the best you can do. My everyday GIS program is ArcGIS. How I can use ...
5
votes
2answers
150 views

Monitoring programmes

I am not sure if it is a right place to ask this one but let me try. Monitoring programmes are known for various targets and for various spatial levels. They may include regions, countries or even ...
11
votes
1answer
2k views

Using R with ArcGIS Desktop

In response to comments below, a re-phrasing of the question. I've used the integration of R with QGIS, and found it a very uesful tool. Having taken a look at the R toolbox extension for 9 and the ...
31
votes
9answers
10k views

Open source methods for kriging?

I have a point dataset which I'd like to Krige, ideally using an open-source software package. If possible, I'd also like to choose the semi-variogram model during the process to improve the ...