fvcom_array_to_df: Convert an FVCOM array to a dataframe for 'plot_field_2d'

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

Convert an FVCOM array to a dataframe for plot_field_2d

Description

This function converts an FVCOM array to a dataframe that, for a snapshot in time, contains the values of the cell at each specified ID; i.e, a 2-dimensional field that can be plotted using plot_field_2d.

Usage

fvcom_array_to_df(data, hour, layer = NULL, ID)

Arguments

data	A 2- or 3-dimensional array outputted by FVCOM for an environmental variable.
hour	An integer specifying single hour (i.e. row) for which to extract model outputs.
layer	An integer specifying a single layer for which to extract inputs. This is only required for 3-dimensional variables.
ID	A numerical vector of columns (i.e. mesh IDs) for which to extract data.

Value

A dataframe with two columns: ID (a unique identifier for each node) and fvcom, the value resolved by FVCOM for the snapshot in time and, if applicable, the layer specified.

Note

The function extracts the values for the hours, layers and mesh IDs supplied from the array using indexing (since FVCOM outputs may not have column names defining mesh IDs). This means that a full array must be supplied for the outputs for the correct cells to be extracted: if the array is subsetted before being passed to this function, then the value at row 1, layer 1 and sheet 1 may not be reflective of hour, layer and mesh cell 1.

Author(s)

Edward Lavender

Examples

#### Step 1: Load in some WeStCOMS files...
# Define directory of the folder containing temperatures:
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)
#### Step 2: Convert sample matrix to a dataframe for plotting...
dat_temp <- fvcom_array_to_df(data = sample,
                              hour = 1,
                              layer = 1,
                              ID = 1:length(dat_nodexy$node_id)
                              )
#### Step 3: Examine dataframe
head(dat_temp)

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