RSurvey (version 0.4.5)

tran.vector: 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.

Value

• A data frame with rows corresponding to points along a profile. Components associated with each point include: llll{ [,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. }

format

The components associated with vel.vect are as follows: llll{ [,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. }

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