get_inputgrid: Get the input grid for a given survey

In nwfsc-assess/VAST_WestCoast: Estimation and simulation with VAST for the US West Coast

Get the input grid for a given survey

Description

Define the input grid for a given survey, where positive values for each coordinate pair define the area in square kilometers to predict to.

Usage

get_inputgrid(survey, range.depth = c(-35, -Inf), range.lat = c(-Inf, Inf))

Arguments

survey	A character value supplying the survey name. The value is typically an acronym. See createMatrix() for a list of defaults.
range.depth	A vector of two numeric values specifying the range of depth values of interest. Values must be in meters and negative values represent those below sea level and positive values are assumed to be above sea level. The first entry is the shallow value and the second entry is the deeper cutoff. The default value is c(-35, -Inf), which truncates the data to depths deeper than 35 m with no limit on how deep they can be.
range.lat	A vector of two numeric values specifying the range of latitude values of interest. Values must be in decimal degrees. The first entry is the smaller value, i.e., southern border, and the second entry is the larger value, i.e., northern border. The default value is c(-Inf, Inf), which leads to a range of the entire coast and if the input argument is being used to truncate the data, the data is not changed. To limit the data to California use c(32.5, 42) and to limit the data to Washington and Oregon use c(42, 49). These ranges typically match up with the outer ranges of all combined strata you wish to predict to, but this does not have to be the case.

Details

Grid cells within the cowcod conservation area denoted by positive values in the Cowcod column and grid cells with a depth less than 35 m are removed from the prediction area for all surveys. The remaining grid cells are chosen for inclusion in the predicted area based on the "prop..." column that is relevant to the survey of interest. See convert_survey4vast() for column names for a given survey.

Value

A data frame of grid points with associated metadata for each box. The data frame is an augmented version of the california current data frame available in the FishStatsUtils package. The most relevant columns will be those for Latitude (Lat), Longitude (Lon), Depth (in meters), and Area_km2. For Area_km2, a column created by this function, only grid cells that pertain to the survey of interest will have positive values. These grid cells with positive values will be included in the prediction area for the results.

Author(s)

Kelli F. Johnson

nwfsc-assess/VAST_WestCoast documentation built on July 4, 2023, 5:45 p.m.