On Wed, Dec 16, 2009 at 7:19 PM, Giovanni Manghi <[email protected]>wrote:
> Viva, > > > > > Estou a precisar construir um raster através da ferramenta de Kernel > > > Density baseada numa layer de pontos e num dos seus atributos. Já > > > estive a experimentar no gvSIG+Sextante e o resultado não me > > > satisfaz uma vez que só me aceita pixel de 1000 metros. Se diminuir > > > este parâmetro tenho problemas com Java Heap Space (memória). Fui ao > > > grass dentro do qgis e vejo la a função gaussian kernel mas não > > > permite seleccionar um atributo do vector. Alguém tem sugestões??? > > > > > > Obrigado. > > > Abraço Viva, > > > > no QGIS poderá usar o plugin > "SDA4PP" (Spatial Data Analysis for Point Pattern) que, entre as outras, > inclui as seguintes ferramentas: > > > * Interactive Identify Tool: returns the value of > overlapping raster and vector layers at the same > time in one window. It gives more information > about feature than the standard identify tool in > QGIS. > * Quadrat analysis: A method of point pattern > analysis in which the study region is sampled > using a set of similar shapes (quadrats) and > counting the number of events in each. Analysis > of the resulting quadrat counts can help > determine whether the pattern is evenly spaced > or clustered. > * F function: A function in point pattern analysis > based on the cumulative frequency of the > shortest distance between events in a point > pattern and a set of randomly placed locations > in the study area. > * G function: A function in point pattern analysis > based on the cumulative frequency of the > shortest inter- event distances between events > in a point pattern. > * K function: A function in point pattern analysis > based on all the inter-event distances between > events in a point pattern. > * Kernel density estimation: A method of density > estimation making use of kernel functions. For > each event to be included in the density > estimates a kernel function is used to 'spread' > its effect across space. > > > http://ggit.metu.edu.tr/~volkan/screenshots.html<http://ggit.metu.edu.tr/%7Evolkan/screenshots.html> > > Para o plugin funcionar é necessario instalar o pacote estatístico "R" e > algumas suas bibliotecas adicionais. > > Saluti > > -- > Giovanni Manghi > Faunalia.pt > Sistemas de Informação Geográfica Open Source > Portugal > > Web: http://www.faunalia.pt > Email & Jabber: [email protected] > PGP Key available > Tel. + 351 96 7058216 > -- > > Para utilizar "SDA4PP" (Spatial Data Analysis for Point Pattern) é necessário intalar, entre outras coisas, *python-rpy2* e depois os pacotes de R *sp*, *rgdal*, *maptools*, *spatstat*. Acontece que nao consigo instalar *spatstat*, da-me: > install.packages("spatstat", dependencies=TRUE) Warning in install.packages("spatstat", dependencies = TRUE) : argument 'lib' is missing: using '/home/eloi/R/x86_64-pc-linux-gnu-library/2.9' --- Please select a CRAN mirror for use in this session --- Loading Tcl/Tk interface ... done Warning message: In getDependencies(pkgs, dependencies, available, lib) : package ‘spatstat’ is not available Alguma ideia do porque? Estou com Ubuntu 9.10. -- Eloi Ribeiro GIS Analyst 39.45º -4.40º http://eloiribeiro.wordpress.com
_______________________________________________ Portugal mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/portugal
