summarise_field_2d: Calculate summary statistics over 2-dimensional fields

In edwardlavender/fvcom.tbx: An R Toolbox for the Unstructured Grid Finite Volume Community Ocean Model (FVCOM)

Calculate summary statistics over 2-dimensional fields

Description

This function produces summary statistics of the variation in environmental conditions across a mesh on a given day. These statistics can be computed either separately for each specified hour, if the inputted array has a row corresponding to those hours, across all hours, or for a single hour if the inputted array contains a single row.

Usage

summarise_field_2d(
  data,
  row_specific = TRUE,
  funs = list(mean = mean, min = min, max = max)
)

Arguments

data	An n x m matrix, in which n are the hours and m are the mesh cells across which you want to calculate summary statistics.
row_specific	A logical input specifying whether summary statistics should be calculated for every row (i.e. hour) in the matrix (row_specific = TRUE), or all rows (row_specific = FALSE).
funs	A named list of functions that you want to evaluate across all mesh cells for each of the specified hours. Each element in the list should be named with a name that corresponds to the function applied (see Examples).

Value

A dataframe with a row for each hour across which statistics were calculated and a column for each summary statistic. The column names correspond to the names provided in the funs argument.

Author(s)

Edward Lavender

Examples

#### Load in WeStCOMS data and process data as required into a 2-dimensional field:
path <- system.file("WeStCOMS_files/temp", package = "fvcom.tbx", mustWork = TRUE)
# Define the path to the temperature file for 2016-03-01:
pathname <- file.path(path, "160301.mat")
# Read in the file using the R.matlab package:
sample <- R.matlab::readMat(pathname)
# Extract the model output (i.e. the 3-dimensional array) from the list using $data
sample <- sample$data
# Examine the structure of the array:
str(sample)
# For a 3-dimensional variable, define a specific layer across which to calculate summary statistics
sample <- sample[, 1, ]
str(sample)

#### 1) Calculate row- (hour-) specific summary statistics across all mesh cells:
# We have a 2 x 802 matrix; rows 1, 2, correspond to hours 1 and 2 in this case
# ... so to calculate summary statistics across all mesh cells for each hour
# ... apply the summarise2sfields as follows:
ls <- summarise_field_2d(data = sample,
                       row_specific = TRUE,
                       funs = list(mean = mean, min = min, max = max, sd = stats::sd)
                       )
# Examine outputs:
ls

#### 2) Calculate summary statistics across all rows (hours) and mesh cells:
ls <- summarise_field_2d(data = sample,
                       row_specific = FALSE,
                       funs = list(mean = mean, min = min, max = max, sd = stats::sd)
                       )
ls

edwardlavender/fvcom.tbx documentation built on Nov. 26, 2022, 10:28 p.m.