tran.vector {RSurvey}R Documentation

Longitudinal and Transverse Velocity Calculations

Description

Transform velocity components form x and y directions to longitudinal and transverse directions.

Usage

tran.vector(vertices, vel.vect, arrow.max)

Arguments

vertices a matrix with rows corresponding to the transect vertices and columns to x and y values.
vel.vect a data frame with rows corresponding to the raster point records and columns to vector components, see Format section for further details.
arrow.max the maximum transverse velocity arrow symbol length.

Format

The components associated with vel.vect are as follows:
[,1] x numeric velocity component in the x-direction.
[,2] y numeric velocity component in the y-direction.
[,3] z numeric velocity component in the z-direction, positive upward.

Value

A data frame with rows corresponding to points along a profile. Components associated with each point include:
[,1] magn numeric the magnitude of the velocity within the principle direction.
[,2] long numeric longitudinal velocity component, perpendicular to the local x-direction.
[,3] arrow.x numeric the velocity component in the local x-direction.
[,4] arrow.y numeric the velocity component in the local z-direction.

Author(s)

Fisher, J. C.

Examples

vert <- matrix(c(0, 0, 10, 10), nrow = 2, ncol = 2, 
        byrow = TRUE, dimnames = list(c("1", "2"), c("x", "y")))
vect <- data.frame(cbind(x = c(1, -2, -3), y = c(-1, 2, -3), z = c(-1, 1, -1)))
tran.vector(vert, vect, 20)

##          magn      long       arrow.x   arrow.y
## [1,] 1.732051 -1.414214  2.809440e-16 -4.588315
## [2,] 3.000000  2.828427 -1.299754e-15  4.588315
## [3,] 4.358899  0.000000 -1.946657e+01 -4.588315

[Package RSurvey version 0.4.5 Index]