From polyanneaguiar at gmail.com Mon Feb 18 17:08:37 2013 From: polyanneaguiar at gmail.com (Polyanne Aguiar) Date: Mon, 18 Feb 2013 16:08:37 -0000 Subject: [Bfast-commits] FW: Running bfast on raster bricks Message-ID: <003601ce0df2$3285f690$9791e3b0$@gmail.com> Hello, I am using the bfast in my jobs. But, I am attempting run the bfastmonitor on a raster brick (time serie MODIS EVI), I not get. I followed the script proposed by you in this forum. But I did not succeed. Following is the script used: ############################################################################ #### ## TUTORIAL for processing raster bricks (satellite image time series of 16-day NDVI images) file<- brick("MT_micro.tif", native, package="raster") file ## helper function for the calc function xbfast <- function(file) { ndvi <- ts(file, frequency=23, start=c(2000,9)) result <- bfast(ndvi, season="harmonic", max.iter=1, breaks=2) return(cbind(result$Magnitude,result$Time)) ## save magnitude and time of the biggest break } ## apply on a single pixel for testing pixel <- as.vector(file[50]) ndvi <- ts(pixel, frequency=23, start=c(2000,9)) plot(ndvi) result <- bfast(ndvi, season="harmonic", max.iter=1, breaks=2) plot(result) ## apply on a single pixel using the xbfast function output <- xbfast(pixel) output ## optimise function that takes into account the percentage of NA's within a time series bfastfun <- function(y) { percNA <- apply(y, 1, FUN=function(x) (sum(is.na(x))/length(x)) ) ## checks the percentage of NA's with the time series i <- (percNA<0.2) res <- matrix(NA, length(i), 2) if (sum(i) > 0) { res[i,] <- t(apply(y[i,], 1, xbfast)) } res } ##apply on the full satellite image time series magntime <- calc(data, fun=bfastfun) layerNames(magntime) <- c("Magnitude", "Time of biggest Break") plot(magntime) ## two rasters are returned: i.e. the magnitude and time of the biggest break ## WARNING: this is requires some time :-). ############################################################################ ################### Thanks, Polyanne Aguiar dos Santos Master in Applied Ecology - UFLA Specialist in Environmental Management - UNISAM Biologist - ESFA Phone: +55 35 9178 3275 Skype: polyanne.aguiar cid:image001.png at 01CDF3FB.781F9910 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 11326 bytes Desc: not available URL: