dipfix: Fix Dip

Description

Fix dip and strike of planes so that they fall in the correct quadrant. The provided quadrant is the determining factor. If unavailable or not helpful, the sign of the dip is used as determining factor.

Usage

dipfix(strike, dip, quadrant = NA, inverted = NA)

Value

a list of the corrected strike, dip and quadrant

Arguments

strike: strike of the data; it is the angle from the north of the horizontal line of the plane. Corrected, its range goes from 0° to 360°.
dip: dip of the data; it is the angle from the horizontal taken on the line of the plane perpendicular to the one of the strike. In other words it is the plane's maximum angular deviation from the horizontal. It is positive downward, and ranges from +90° for straight down to -90° for straight up. Dip values in [-180,-90] or/and ]90,180] indicate inversion of the plane.
quadrant: the quadrant where the plane dips downward. Accepted values are NA, 'N', 'S', 'W' or 'E' (lower- or uppercase alike). Is independant of inversion
inverted: whether the plane is upside down.

Details

the strike will be corrected as the orientation of the dip (i.e. downward) minus 90°; it ranges from 0 to 360°. It is determined firstly from the quadrant. If the quadrant is missing or not helpful (e.g. 'N' or 'S' for a strike of 0° or 180°, 'E' or 'W' for a strike of 90° or 270°), it is determined using the sign of the dip. Inversion will be indicated if the dip values are in [-180,-90] or/and ]90,180], or simply if inverted = T. The inversion does not influence the calculation of the strike, dip and quadrant: whether the plane is upside down does not change these parameters output.

Examples

Run this code

strike   <- c(-60, 180,20,0,20)
dip      <- c(-60,20,-45,110,-90)
quadrant <- c("N",NA,NA,NA,"E")
inverted <- c(FALSE,TRUE,FALSE,TRUE,FALSE)

dipfix(strike,dip,quadrant,inverted)

dipfix(strike,dip,quadrant)