Senhores, bom dia!

Fiz mais uns testes, com 3 alternativas {raster, ncdf4, RNetCDF} para escrever o arquivo NetCDF a partir de uma matriz. Acredito que seja possível melhorar o script do RNetCDF. Se alguém puder colaborar, será bem-vindo.

### <code r>

### Dados

require(raster)

data(volcano); volcano <- 10*volcano

image(volcano)

x <- 100*(1:nrow(volcano))

y <- 100*(1:ncol(volcano))

########## {ncdf4} ###########################################################

# browseURL("https://www.getdatajoy.com/learn/Read_and_Write_NetCDF_from_R")

library(ncdf4)

nc1_dim1 <- ncdim_def('EW', 'm', as.double(x))

nc1_dim2 <- ncdim_def('SN', 'm', as.double(y))

nc1_varz <- ncvar_def('Elevation', 'm', list(nc1_dim1, nc1_dim2), -1, longname = 'Data about a Volcano')

nc1_out <- nc_create('volcano.nc', nc1_varz, force_v4 = TRUE)

ncvar_put(nc1_out, nc1_varz, volcano)

nc_close(nc1_out)

print(nc_open("volcano.nc"))

plot(raster("volcano.nc"))

########## {RNetCDF} #########################################################

# browseURL("https://journal.r-project.org/archive/2013-2/michna-woods.pdf")

require(RNetCDF)

nc2_out <- create.nc("volcano2.nc")

dim.def.nc(nc2_out, "EW", length(x))

dim.def.nc(nc2_out, "SN", length(y))

var.def.nc(nc2_out, "EW", "NC_DOUBLE", "EW")

var.def.nc(nc2_out, "SN", "NC_DOUBLE", "SN")

var.def.nc(nc2_out, "Elevation", "NC_DOUBLE", c("EW", "SN"))

att.put.nc(nc2_out, "Elevation", "_FillValue", "NC_DOUBLE", -999.9)

var.put.nc(nc2_out, "EW", as.double(x))

var.put.nc(nc2_out, "SN", as.double(y))

var.put.nc(nc2_out, "Elevation", volcano)

close.nc(nc2_out)

print(nc_open("volcano2.nc")) ### {ncdf4}

print.nc(open.nc("volcano2.nc")) ### {RNetCDF}

var.get.nc(nc2, "EW")

var.get.nc(nc2, "Elevation")

plot(raster("volcano2.nc"))

########## {raster} ##########################################################

require(raster)

tmp <- raster(volcano)

r <- t(flip(tmp, 1))

plot(r)

extent(r) <- c(range(x), range(y))

plot(r)

writeFormats()

writeRaster(r, "volcano3.nc", "CDF")

print(nc_open("volcano3.nc")) ### {ncdf4}

plot(raster("volcano3.nc"))

### </code>

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Éder Comunello

Agronomist (UEM), MSc in Environ. Sciences (UEM)

DSc in Agricultural Systems Engineering (USP/Esalq)

Brazilian Agricultural Research Corporation (Embrapa)

Dourados, MS, Brazil |<O>|

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GEO, -22.2752, -54.8182, 408m

UTC-04:00 / DST: UTC-03:00