Latest Contributions by LaurenRosenshein

Hi Jeanee, You hit the nail on the head!  When you run Moran's I and do not choose to provide a Spatial Weights Matrix from File, then the tool is essentially creating a SWM on the fly based on the options you filled out for Conceptualization of Spatial Relationships, Distance Method, Standardization, and Distance Band or Threshold Distance.  All of those options enable the tool to define spatial relationships on the fly.  There are some additional options for defining spatial relationships when you use the Generate Spatial Weights Matrix tool, so it is really up to you whether you need to use a SWM or you can define your relationships adequately using the on-the-fly methods. ... View more

Hi Mareike, I'm really sorry that you're having trouble! Would it be possible for you to attach a copy of the graphical output from K-Function?  That would help us start to figure out exactly what's going on.  Hopefully we'll be able to figure this out and get you up and running! Lauren Rosenshein Geoprocessing Product Engineer ... View more

Hi Remi, I'm really sorry that you're having trouble with the supplementary spatial statistics tools!  In order for us to try and reproduce the issue, can you please tell us exactly what operating system, version of ArcGIS, and regional language settings are.  This way we can set up a machine that matches yours and try to reproduce the issue.  It would also be very helpful if you could try changing your regional language settings to English.  If you still are having trouble running the tools (meaning that localization issues are not the problem), then we will have to investigate further.  Either way, thank you very much for bringing this to our attention.  It will help us make sure that these tools work as expected when they are released officially with 10.1, and hopefully we'll be able to help you get them running on your own machine in the meantime. Lauren Rosenshein Geoprocessing Product Engineer ... View more

Hi Juan, I'm glad that you found the tutorial useful.  Actually, there are quite a few ways to dig deeper into the algorithms and methods behind the hot spot analysis tool.  For one thing, the documentation called How Hot Spot Analysis Works outlines the algorithms that are used for a hot spot analysis.  Another great way to learn more about the tools, especially if you are interested in implementing something similar on your own, is to actually look at the source code associated with the tools.  Most of the tools in the Spatial Statistics toolbox are delivered as python scripts.  From the ArcToolbox Window, if you right-click on the Hot Spot Analysis tool and choose "Edit" you can actually see the code, which is a great way to learn more about the method. As far as your questions about the definitions, could you be a little more specific about the context of the question?  Where did you see those terms used?  Knowing where you saw those terms used will help be figure out the best way to explain them in context. ... View more

Hi Thomas, You can definitely use the Spatial Statistics tools to evaluate how clustered or dispersed the distribution of your data is, or the distribution of values associated with your data, whether it's points, lines, or polygons.  There are quite a few different tools you can use to do that type of analysis, all depending on the question that you are asking or the problem that you're trying to solve.  Some tools that you might want to look into are the Average Nearest Neighbor tool, the Ripley's K Function tool, or the Spatial Autocorrelation tool, to name a few.  You might also want to see the general descriptions of all of the tools for measuring global clustering ( Analyzing Patterns ) and local clustering ( Mapping Clusters ).  Hopefully these resources will help you get started.  You can also check out some additional tutorials, videos, and web seminars about the Spatial Statistics tools here:  http://esriurl.com/spatialstats . Also, just so you know, several of the tools in the Spatial Statistics toolbox do optionally take a Spatial Weights Matrix as an input.  The Spatial Weights Matrix helps you define, ahead of time, how features are related in space. ... View more

Hi Terry, You are absolutely right, the Hot Spot Analysis tool should be working on your selection set.  In order to figure out exactly what the problem is, I'm hoping you can try a few things and answer a few questions to narrow it down. 1. When you use "Select by attributes" on the dataset, do the correct features appear selected in the map?  If you open the attribute table with the selection do you see those features are selected?  --If the answers to these questions aren't "yes" (ie the selection isn't working) it sounds like it is a problem with the selection, potentially with your query.  Try the same thing with your definition query, too. 2. With the data selected, can you please try running another tool?  Something simple, like maybe copy features or buffer.  We want to make sure that your selection is being honored by other tools that are supposed to honor selections.  If it isn't, then we may have an issue with selections and/or your dataset.  If the selection is being honored, then would it be possible for you to share your data with us so that we can try to reproduce the issue and figure out what's going on? So sorry you're having trouble, and hopefully we can get it figured out quickly! Lauren Rosenshein Geoprocessing Product Engineer ... View more

Hi Chris, This is a good question, and my initial reaction is that this does not sound like a bug (although I do understand your concern).  The first part of your question involves clipping a dataset that was originally created using the Generate Random Points tool.  Once you clip those random points, depending on the polygon that you're using to clip the points you may be imposing a structure on what were once randomly distributed points, which could lead to a clustered distribution. In terms of the new dataset that you created using the Australia boundary, what does that constraining dataset look like?  Is it one polygon representing Australia, or does it have multiple polygons?  If it has multiple polygons (regions, counties, etc.), then Generate Random Points actually generates a user-specified random number of points in each one of those polygons.  What that means is that if you have smaller polygons and larger polygons within that constraining dataset, then there will be 100 points (for example) in each one of the smaller polygons and 100 points in each one of the larger polygons.  What that means is that within each individual polygon the features will be "random", but for the entire study area you will have imposed some definite clustering in those smaller polygons.  So that's one thing to think about. The other thing to think about, which is touched in a little bit on the documentation for Average Nearest Neighbor , is how sensitive the Average Nearest Neighbor (ANN) tool is to the study area or extent of your analysis.  Essentially what ANN does is look at the average distance between each feature and its closest feature in relation to the area of the analysis and compare that to the distances between random features in a circle of the same area.  So, for instance, the same exact distribution of points could be considered random or clustered depending on the extent/bounding geometry used for the analysis.  For this reason, one of the ways that we recommend using ANN is actually for making comparisons between multiple distributions within the same study area.  For instance, if you had points represnting the locations of various types of trees in Australia, you could use ANN to compare those distributions because the point locations/distributions would be changing, but the bounding geometry would stay the same.  That isn't to say that you cannot use ANN for your purposes, it is just important to remember the impact that your bounding geometry has on your output. ... View more

Hi Vicki, In ArcGIS 10, there is a Geoprocessing drop-down menu along the top bar of your ArcMap window.  From the Geoprocessing drop-down there is the option to open Modelbuilder.  From there, most things should be pretty similar.  If you're having trouble finding the tools that you need, don't forget that you can Search For Tools, which is also an option available from the Geoprocessing drop-down menu. ... View more

Hi Michal, I'm really sorry that you're having trouble with GWR! In order to try to figure out what's going on, if you can provide the following information we can try to reproduce your problem and hopefully fix it! -What version of ArcGIS are you using? -What operating system are you using? -What kind of data are you using? Polygons, points, lines? How many features are there? Are they are in a personal geodatabase, a file geodatabase, shapefiles, or other? If possible, if you could provide the dataset that was giving you trouble that would be very helpful in trying to reproduce. If this is possible, it will also be helpful to get screenshots of the tool dialogs before you run them, so that we know exactly the parameter choices you're making. If not, the above information should at least get us on the right track. Again, I'm very sorry that you're having trouble, and we'll do our best to figure it out! Lauren Rosenshein Geoprocessing Product Engineer ... View more