[R] Problem with converting grib file to excel
javad bayat
j@b@y@t194 @end|ng |rom gm@||@com
Thu Sep 26 22:22:12 CEST 2024
Dear Roy,
Sorry for my mistake, I thought I have uploaded the grib file.
I really apologise for that. I will send it on Saturday.
Thank you very much.
On Thu, 26 Sept 2024, 17:40 Roy Mendelssohn - NOAA Federal, <
roy.mendelssohn using noaa.gov> wrote:
> 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.bayat194 using 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 using 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 <polc1410 using 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.4567 using 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.bayat194 using 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(t2m_values)) || any(is.na(d2m_values)) || any(is.na
>> >> (tcc_values))
>> >>> || any(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: bayat194 using yahoo.com
>> >>>
>> >>> [[alternative HTML version deleted]]
>> >>>
>> >>> ______________________________________________
>> >>> R-help using 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 using 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 using 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.Mendelssohn using 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 using 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: bayat194 using yahoo.com
>
>
>
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