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I have a code in R that extracts daily values of every month from a single .nc4 file. I have 49 netcdf files. i want to extract the data from all those files using loop and write them in a unique csv file.

I have this code for a single file but I need help for multiple files.

    flux1701 <- nc_open(list[14])
GPP.array1701 <- ncvar_get(flux1701, "GPP")
fillvalue1701 <- ncatt_get(flux1701, "GPP", "_FillValue")
nc_close(flux1612)
GPP.array1701[GPP.array1701 == fillvalue$value] <- NA
rbrick1701 <- brick(GPP.array1701, xmn=min(lat), xmx=max(lat), ymn=min(lon), ymx=max(lon), crs=CRS("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs+ towgs84=0,0,0")) ##to convert the entire 3d array of data to a raster brick
rbrick1701 <- flip(t(rbrick1701), direction='y')
qro_lon <- -99.941
qro_lat <-  20.717
qro_series1701 <- extract(rbrick1701, SpatialPoints(cbind(qro_lon,qro_lat)), method='simple')
qro_df1701 <- data.frame(day= seq(from=1, to=31, by=1), GPP=t(qro_series1612))
write.csv(qro_df1701, file="qro201701.csv")
Jacky_r
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1 Answers1

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I do not think your code gives you the correct extent . I would suggest doing

library(raster)
rbrick1701 <- brick(list[14], "GPP")

And here is one of many examples/answers on how to write a loop

Robert Hijmans
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