prof brian ripley ripleystatsoxacuk lets crosspost ill pick one point general relevance list rhelp tue 5 aug 2008 matt oliver wrote try memorylimitsize4000 4gb memory system guaranteed solve problem though assuming windows looks like limiting issue 32bit system memory ram address space using memorylimitsize4000 still get 2gb address space unless use 3gb flag see rwfaq q29 big datasets like lidar much better getting access 64bit system ton ram 64gb well better even 4gb ram addressspace issues even 2gb 32bit os windows used run dualboot windows xp 64bit linux box 2gb firsthand experience cheers matt tue aug 5 2008 147 pm alessandro wrote hi phd student forestry science working lidar data set huge data set brandnew r geostatistic sorry background forestry wish improve skill improve wish develop methodology processing large dataset points typical lidar problem memory created subsample database semivariogram periodic shape able try fit model maximum two weeks work day bay day sorry geostatistical user happy listen suggests data format x z height create dem txt format questions 1 random selection 10000 points fitsemivariogram model possible use lidar points new lidar power use huge number points xy z value create high resolution map dem vegetation problem memory use clusterlinux network improve capacity r 2 possible improve memory capacity 3 data trend qqplot shows gaussian trend possible normalize data ie log 4 use r code subgrounduk krigelogzxy subground newgrid vfit nmax40 appear error massage error evalexpr envir enclos oggetto x non trovato send report attach image explain better procedure write rsoftware improve gstat number points ground dataset 4x2 km 545991600 random sub set original dataset 10000 r code samplerows sample1nrowtestgroundsize10000replacefalse subground testgroundsamplerows 1 original dataset histogram show two populations 2 original dataset density plot show two populations data 3 original dataset boxplot show arent outlayers un dataset classification terrascan good therefore isnt problem original data 4 ordinary kriging show trend space hypothesis points close space 5 detrend dataset v variogram logzxy subground cutoff1800 width100 6 map semivariogram show anisotropy space 0 nord 135 major radius 45 minus radius 7 semivariogram anisotropy 0 45 90 135 shows best shape 135 8 semivariogram fit gaussian model r code see fig v variogramzxy subground cutoff1800 width200 alphac135 vfit fitvariogramv vgmpsill 1 modelgau range1800 nugget 0 anisc135 05 r code testground2 readtablefilecwork_lidar_usar_kriging_new_setground_26841492694149_xyztxt headert class testground2 coordinates testground2xy makes testground spatialpointsdataframe class testground2 strasdataframetestground histtestgroundznclass20 makes histogram plotdensitytestgroundz makes plot density boxplottestgroundzthis makes boxplot samplerowssample1nrowtestgroundsize10000replacefalse select n points database subground testgroundsamplerows histsubgroundznclass20 makes histogram plotdensitysubgroundz makes plot density boxplotsubgroundzthis makes boxplot spplotsubgroundz colregionsbpycolors seq850117010 librarymaptools librarygstat plotvariogramz1 subground ordinary kriging without detrend trend must use detrend fuction zxy x11 plotvariogramlogzxy subground cutoff1800 width80 universal kriging detrend x11 plotvariogramlogzxy subground cutoff1800 width80 mapt x11 plotvariogramlogzxy subground cutoff1800 width80 alphac0 45 90 135 v variogramlogzxy subground cutoff1800 width80 alphac135 45 vfit fitvariogramv vgmpsill 1 modelgau range1800 nugget 0 anisc135 05 plotv vfit plotnuf pch create new grid newgrid spsamplesubground typeregular cellsizec11 griddednewgrid true fullgridnewgrid true newgridgrid using universal kriging subgrounduk krigelogzxy subground newgrid vfit nmax40 error brian ripley ripleystatsoxacuk professor applied statistics httpwwwstatsoxacukripley university oxford tel 44 1865 272861 self 1 south parks road 44 1865 272866 pa oxford ox1 3tg uk fax 44 1865 272595 ______________________________________________ rhelprprojectorg mailing list httpsstatethzchmailmanlistinforhelp please read posting guide httpwwwrprojectorgpostingguidehtml provide commented minimal selfcontained reproducible code wed 06 aug 2008 040515 0100 r rsiggeo lidar problem r thanks help