# SHmax direction resulting from multiple plate boundaries

Source:`R/model_shmax.R`

`superimposed_shmax.Rd`

Calculates a \(\sigma_{Hmax}\) direction at given coordinates, sourced by multiple plate boundaries. This first-order approximation is the circular mean of the superimposed theoretical directions, weighted by the rotation rates of the underlying PoRs.

## Arguments

- df
`data.frame`

containing the coordinates of the point(s) (`lat`

,`lon`

), and the direction of \(\sigma_{Hmax}\)`azi`

(in degrees)- PoRs
multirow

`data.frame`

or`"euler.pole"`

object that must contain`lat`

,`lon`

and`angle`

- types
character vector with length equal to number of rows in

`PoRs`

. Type of plate boundary. Must be`"out"`

,`"in"`

,`"right"`

, or`"left"`

for outward, inward, right-lateral, or left-lateral moving plate boundaries, respectively.- absolute
logical. Whether the resultant azimuth should be weighted using the absolute rotation at the points or the angular rotation of the PoRs.

- PoR_weighting
(optional) numeric vector with length equal to number of rows in

`PoRs`

. Extra weightings for the used PoRs.

## Value

two column vector. `azi`

is the resultant azimuth in degrees /
geographical CRS), `R`

is the resultant length.

## See also

`superimposed_shmax_PB()`

for considering distances to plate boundaries

## Examples

```
data(san_andreas)
data(nuvel1)
pors <- subset(nuvel1, plate.rot %in% c("eu", "na"))
res <- superimposed_shmax(san_andreas, pors, types = c("in", "right"), PoR_weighting = c(2, 1))
head(res)
#> azi R
#> [1,] 156.6593 0.6609390
#> [2,] 150.5433 0.6532568
#> [3,] 155.9269 0.6555497
#> [4,] 157.0336 0.6434240
#> [5,] 155.9564 0.5960833
#> [6,] 152.3433 0.5636785
```