Hi Javad: I know a lot about reading GRIB files, I work with them all the time. But if you don’t make the file available, or point me to where I can download it, there is not much I can do.
Thanks, -Roy > On Sep 25, 2024, at 9:41 PM, javad bayat <j.bayat...@gmail.com> wrote: > > Dear all; > Many thanks for your responses. Actually it is not completely a GIS file, it > is a data file which stores meteorological data of a specific region. But the > site allows downloading with grib format and as I searched to read this type > of file in R, I found the Raster Package. > In python it is possible to do this using cdsapi and xarray library, but I am > not familiar with python. > Sincerely > > On Thu, Sep 26, 2024 at 2:33 AM Roy Mendelssohn - NOAA Federal via R-help > <r-help@r-project.org <mailto:r-help@r-project.org>> wrote: >> At least for me the dataset file did not come through. I will look at it if >> it can be made available. It does look like the finial step of reading the >> data into raster failed, so then did the rest of th commands. >> >> -Roy >> >> >> > On Sep 25, 2024, at 3:24 PM, CALUM POLWART <polc1...@gmail.com >> > <mailto:polc1...@gmail.com>> wrote: >> > >> > Noticeable lack of silence in the group on this one. >> > >> > I've not got time to test currently. But my experience of geo location >> > files - they often had more than 2 dimensional data. In other words you >> > might have a boundary of a region as an object with long and lat for maybe >> > 100 data points making up the region. So 200 pieces of data. All held as a >> > list or something similar in a single "cell" as excel would refer to it. >> > >> > My gut feeling is that's likely to make export to excel difficult without >> > data carpentry first? >> > >> > On Tue, 24 Sep 2024, 21:26 Bert Gunter, <bgunter.4...@gmail.com >> > <mailto:bgunter.4...@gmail.com>> wrote: >> > >> >> You might try posting on r-sig-geo if you don't get a satisfactory >> >> response here. I assume there's a lot of expertise there on handling >> >> raster-type data. >> >> >> >> Cheers, >> >> Bert >> >> >> >> On Mon, Sep 23, 2024 at 11:31 PM javad bayat <j.bayat...@gmail.com >> >> <mailto:j.bayat...@gmail.com>> wrote: >> >>> >> >>> Dear R users; >> >>> I have downloaded a grib file format (Met.grib) and I want to export its >> >>> data to excel file. Also I want to do some mathematic on some columns. >> >> But >> >>> I got error. I would be more than happy if anyone can help me to do >> >> this. I >> >>> have provided the codes and the Met.grib file in this email. >> >>> Sincerely yours >> >>> >> >>> # Load the necessary libraries >> >>>> library(raster) # For reading GRIB files >> >>>> library(dplyr) # For data manipulation >> >>>> library(lubridate) # For date manipulation >> >>>> library(openxlsx) # For writing Excel files >> >>> >> >>> # Specify the file paths >> >>>> grib_file_path <- "C:/Users/Omrab_Lab/Downloads/Met.grib" >> >>>> excel_file_path <- "C:/Users/Omrab_Lab/Downloads/Met_updated.xlsx" >> >>> >> >>> # Open the GRIB file >> >>>> raster_data <- stack(grib_file_path) >> >>> >> >>> # Check the names of the layers to identify which ones to extract >> >>>> layer_names <- names(raster_data) >> >>>> print(layer_names) # Prints >> >>> >> >>> >> >>>> # Extract layers based on layer names - adjust as necessary >> >>>> t2m <- raster_data[[grep("t2m", layer_names)]] >> >>>> d2m <- raster_data[[grep("d2m", layer_names)]] >> >>>> tcc <- raster_data[[grep("tcc", layer_names)]] >> >>>> valid_time <- raster_data[[grep("valid_time", layer_names)]] >> >>>> t2m >> >>> class : RasterStack >> >>> nlayers : 0 >> >>> >> >>>> # Check if the raster layers are loaded correctly >> >>>> if (is.null(t2m) || is.null(d2m) || is.null(tcc) || >> >> is.null(valid_time)) >> >>> { >> >>> + stop("One or more raster layers could not be loaded. Please check >> >> the >> >>> layer names.") >> >>> + } >> >>> >> >>>> # Convert raster values to vectors >> >>>> t2m_values <- values(t2m) >> >>> Error in dimnames(x) <- dn : >> >>> length of 'dimnames' [2] not equal to array extent >> >>>> d2m_values <- values(d2m) >> >>> Error in dimnames(x) <- dn : >> >>> length of 'dimnames' [2] not equal to array extent >> >>>> tcc_values <- values(tcc) >> >>> Error in dimnames(x) <- dn : >> >>> length of 'dimnames' [2] not equal to array extent >> >>>> valid_time_values <- values(valid_time) >> >>> Error in dimnames(x) <- dn : >> >>> length of 'dimnames' [2] not equal to array extent >> >>> >> >>> # Check for NA values and dimensions >> >>> if (any(is.na <http://is.na/>(t2m_values)) || any(is.na >> >>> <http://is.na/>(d2m_values)) || any(is.na <http://is.na/> >> >> (tcc_values)) >> >>> || any(is.na <http://is.na/>(valid_time_values))) { >> >>> warning("One or more layers contain NA values. These will be removed.") >> >>> } >> >>> >> >>> # Create the data frame, ensuring no NA values are included >> >>> df <- data.frame( >> >>> t2m = t2m_values, >> >>> d2m = d2m_values, >> >>> tcc = tcc_values, >> >>> valid_time = valid_time_values, >> >>> stringsAsFactors = FALSE >> >>> ) >> >>> >> >>> # Remove rows with NA values >> >>> df <- na.omit(df) >> >>> >> >>> # Convert temperatures from Kelvin to Celsius >> >>> df$t2m <- df$t2m - 273.15 >> >>> df$d2m <- df$d2m - 273.15 >> >>> >> >>> # Calculate relative humidity >> >>> calculate_relative_humidity <- function(t2m, d2m) { >> >>> es <- 6.112 * exp((17.67 * t2m) / (t2m + 243.5)) >> >>> e <- 6.112 * exp((17.67 * d2m) / (d2m + 243.5)) >> >>> rh <- (e / es) * 100 >> >>> return(rh) >> >>> } >> >>> df$RH <- calculate_relative_humidity(df$t2m, df$d2m) >> >>> >> >>> # Convert valid_time from numeric to POSIXct assuming it's in seconds >> >> since >> >>> the epoch >> >>> df$valid_time <- as.POSIXct(df$valid_time, origin = "1970-01-01") >> >>> >> >>> # Extract year, month, day, and hour from valid_time >> >>> df$Year <- year(df$valid_time) >> >>> df$Month <- month(df$valid_time) >> >>> df$Day <- day(df$valid_time) >> >>> df$Hour <- hour(df$valid_time) >> >>> >> >>> # Select only the desired columns >> >>> df_selected <- df %>% select(Year, Month, Day, Hour, tcc, t2m, RH) >> >>> >> >>> # Save the updated DataFrame to an Excel file >> >>> write.xlsx(df_selected, excel_file_path, row.names = FALSE) >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> -- >> >>> Best Regards >> >>> Javad Bayat >> >>> M.Sc. Environment Engineering >> >>> Alternative Mail: bayat...@yahoo.com <mailto:bayat...@yahoo.com> >> >>> >> >>> [[alternative HTML version deleted]] >> >>> >> >>> ______________________________________________ >> >>> R-help@r-project.org <mailto:R-help@r-project.org> mailing list -- To >> >>> UNSUBSCRIBE and more, see >> >>> https://stat.ethz.ch/mailman/listinfo/r-help >> >>> PLEASE do read the posting guide >> >> https://www.R-project.org/posting-guide.html >> >> <https://www.r-project.org/posting-guide.html> >> >>> and provide commented, minimal, self-contained, reproducible code. >> >> >> >> ______________________________________________ >> >> R-help@r-project.org <mailto:R-help@r-project.org> mailing list -- To >> >> UNSUBSCRIBE and more, see >> >> https://stat.ethz.ch/mailman/listinfo/r-help >> >> PLEASE do read the posting guide >> >> https://www.R-project.org/posting-guide.html >> >> <https://www.r-project.org/posting-guide.html> >> >> and provide commented, minimal, self-contained, reproducible code. >> >> >> > >> > [[alternative HTML version deleted]] >> > >> > ______________________________________________ >> > R-help@r-project.org <mailto:R-help@r-project.org> mailing list -- To >> > UNSUBSCRIBE and more, see >> > https://stat.ethz.ch/mailman/listinfo/r-help >> > PLEASE do read the posting guide >> > https://www.R-project.org/posting-guide.html >> > <https://www.r-project.org/posting-guide.html> >> > and provide commented, minimal, self-contained, reproducible code. >> >> ********************** >> "The contents of this message do not reflect any position of the U.S. >> Government or NOAA." >> ********************** >> Roy Mendelssohn >> Supervisory Operations Research Analyst >> NOAA/NMFS >> Environmental Research Division >> Southwest Fisheries Science Center >> ***Note new street address*** >> 110 McAllister Way >> Santa Cruz, CA 95060 >> Phone: (831)-420-3666 >> Fax: (831) 420-3980 >> e-mail: roy.mendelss...@noaa.gov <mailto:roy.mendelss...@noaa.gov> www: >> https://www.pfeg.noaa.gov/ >> >> "Old age and treachery will overcome youth and skill." >> "From those who have been given much, much will be expected" >> "the arc of the moral universe is long, but it bends toward justice" -MLK Jr. >> >> ______________________________________________ >> R-help@r-project.org <mailto:R-help@r-project.org> mailing list -- To >> UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> https://www.R-project.org/posting-guide.html >> <https://www.r-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. > > > -- > Best Regards > Javad Bayat > M.Sc. Environment Engineering > Alternative Mail: bayat...@yahoo.com <mailto:bayat...@yahoo.com> [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
