cl_Transect: Extracts a transect from data returned by function...

In jpgattuso/CoastalLight: Available Light on the Coastal Ocean [0-200m] Floor

Description

When it is operated with type "Area" function cl_GetData() returns data at all available points of a geographic area; function cl_Transect() extract a transect inside this area in 2 steps;

• rasterization of the data

• extraction of the transect

output of this function has the same structure as output of function cl_GetData() and may be plotted by function cl_PlotData()

Usage

cl_Transect(x, vertices, plt = FALSE)

Arguments

x	: [list] a list returned by function cl_GetData() whose field type has value "Area"
vertices	: [list] a polygonal line that represents a transect; each element of this list is a geographic point, i.e. a vector of length 2 (longitude, latitude);
plt	: [logical] make a plot of the transect on the maps of the variables (default is FALSE)

Value

: [list] a list with 5 components :

• the same 4 components as returned by function cl_GetData() :

  • type : the type of geographical zone; its value is "Transect"

  • lon : identical to component lon of x

  • lat : identical to component lat of x

  • data : a matrix of data along the transect with columns names "longitude", "latitude", and variables requested.

• a fifth component distances which represents the distance traveled from the first vertex of the polygonal line

Examples

gabes <- cl_GetData(lon = c(10, 14), lat = c(32.5, 36), dir = "./CoastalLight.d")
vertices <- list(c(10.1,33), c(13.5,35), c(13,34))
#X11()
par(mfrow = c(3, 2))
tr <- cl_Transect(gabes, vertices, plt = TRUE)
cl_PlotData(tr)

jpgattuso/CoastalLight documentation built on June 25, 2021, 5:34 p.m.