Dear colleagues, I needed to measure the association degree (and ideally its p-value) between two maps, one representing richness of European bryophytes and the other vascular plant richeness. From the maps it is clear the two patterns are reversed: bryophytes 'rule' in the north, and vascular plant richness is higher in southern Europe.
I have used isodata algorithm followed by a Maximum-likelihood classification to generate a map showing four different areas in Europe (lowbryo-lowvasc, lowbryo-highvasc, highbryo-lowvasc, and highbryo-highvasc). Additionally, I would like to run a correlation analysis but corrected for the univariate spatial correlation of each variable (bryophytes and vascular plant richness); a global correlation map-to-map is meaningless here. I found a statistic that would suit my needs (Lee, S.-I. 2001. Developing a bivariate spatial association measure: An integration of Pearson's r and Moran's I. Journal of Geographical Systems 3(4): 369-385). It is implemented in 'The Map Comparison Kit' (http://www.riks.nl/mck/), but it return values outside the -1 to 1 values, which makes me think there is something wrong in the code or the statistic. Can somebody guide me to a R package allowing me to measure the association between these two grids? thanks in advance, Jesús ************************************************************************* Jesús Muñoz PhD e-mail: jmu...@rjb.csic.es Real Jardín Botánico (CSIC) C/ Claudio Moyano 1 tlf. +34 91 420 3017 E-28014 Madrid fax. +34 91 420 0157 ESPAÑA (Spain) http://www.masterenbiodiversidad.org http://www.rjb.csic.es/jardinbotanico/jardin/contenido.php?Pag=413&tipo=cien tifico&cod=66 KRAKEN research group (environmental modelling, data processing & analysis): http://www.unex.es/investigacion/grupos/kraken SYNTHESYS: EU funds short visits to our institution: http://www.synthesys.info/index.htm ************************************************************************* __________ Información de ESET Endpoint Security, versión de la base de firmas de virus 9449 (20140220) __________ ESET Endpoint Security ha comprobado este mensaje. http://www.eset.com [[alternative HTML version deleted]]
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