Compute summary statistics of a netCDF variable

Applies a summary function to a variable in a netCDF file over the dimensions not listed in `MARGIN`, and writes the result to a new netCDF file.

Usage

nc_mean(
  filename,
  varid,
  MARGIN = c(1, 2),
  na.rm = TRUE,
  trim = 0,
  output = NULL,
  drop = TRUE,
  compression = NA,
  verbose = FALSE,
  force_v4 = TRUE,
  ignore.case = FALSE
)

nc_min(
  filename,
  varid,
  MARGIN = c(1, 2),
  na.rm = TRUE,
  output = NULL,
  drop = TRUE,
  compression = NA,
  verbose = FALSE,
  force_v4 = TRUE,
  ignore.case = FALSE
)

nc_max(
  filename,
  varid,
  MARGIN = c(1, 2),
  na.rm = TRUE,
  output = NULL,
  drop = TRUE,
  compression = NA,
  verbose = FALSE,
  force_v4 = TRUE,
  ignore.case = FALSE
)

Arguments

filename

Character string giving the path to the input netCDF file.

varid

Character string giving the name of the variable to process. If missing and the file contains a single variable, that variable is used.

MARGIN

Integer or character vector specifying the dimensions to retain in the output, as in [base::apply()]. Dimension names may be used.

na.rm

Logical. If `TRUE`, missing values are removed before computing the statistic.

trim

Numeric scalar giving the fraction of observations to be trimmed from each end before computing the mean. Passed to [base::mean()]. Used only by `nc_mean()`.

output

Character string giving the path to the output netCDF file to create.

drop

Logical. Currently not implemented.

compression

Optional numeric compression level for the output variable.

verbose

Logical. Currently unused.

force_v4

Logical. Currently unused internally.

ignore.case

Logical. If `TRUE`, ignore case when matching dimension names supplied in `MARGIN`.

Value

Invisibly returns `output`.

Details

`nc_mean()` applies [base::mean()], `nc_min()` applies [base::min()], and `nc_max()` applies [base::max()].

The output retains the dimensions specified in `MARGIN`.

See also

[nc_apply()], [base::mean()], [base::min()], [base::max()]

Examples

if (FALSE) { # \dontrun{
nc_mean(
  filename = "input.nc",
  varid = "temp",
  MARGIN = c("lon", "lat"),
  na.rm = TRUE,
  output = "temp_mean.nc"
)

nc_min(
  filename = "input.nc",
  varid = "temp",
  MARGIN = c("lon", "lat"),
  na.rm = TRUE,
  output = "temp_min.nc"
)

nc_max(
  filename = "input.nc",
  varid = "temp",
  MARGIN = c("lon", "lat"),
  na.rm = TRUE,
  output = "temp_max.nc"
)
} # }