Dear Raul, Any changes in the size {<GS>support</GS>}, shape {<GS>anisotropy</GS>} etc of cells (grids) in cell-based analysis including from spatial analysis (GIS etc) and geostatistics (grided variogram, kriging etc) need to be considered carefully while they can provide very different correlation structure and so result in very different interpretations. Geostatistically speaking, the support effect should be considered initially very well. The support can be simply defined as how your choice (e.g. cell) is being represented with the samples inside it (e.g., number of samples per cell). There are some methods you will find them interesting, I think: For an evaluation of the dispersion of data into cells, consider Morisita (Morishita) factor (e.g., from Kanevsky); Also consider declusterting methods (e.g. from Clayton); ...
Best Regards, Younes yfa.st...@ymail.com http://alghalandis.com ________________________________ ________________________________ From: Raul Sierra Alcocer <raul.sierra.alco...@gmail.com> To: ai-geostats@jrc.it Sent: Tue, 15 March, 2011 3:49:31 AM Subject: AI-GEOSTATS: choosing grid resolution Dear list, I am a PhD student in Computer Science new to spatial analysis, and I am working in a data mining platform at my institute that will provide some tools for spatial data mining. It is basically analysis of spatial features using rectangular grids. My question is if there are any studies about the effects of grid resolution in the results of correlation analysis between spatial features. When I say effects, I mean how the choice of cell size affects the statistical significance of the results. Thanks in advance, Raúl Sierra. --------------------------------------------------------------- Centro de Ciencias de la Complejidad, Universidad Nacional Autonoma de México. + + To post a message to the list, send it to ai-geost...@jrc.ec.europa.eu + To unsubscribe, send email to majordomo@ jrc.ec.europa.eu with no subject and "unsubscribe ai-geostats" in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/