# radSH: Radiation pattern for SH waves In RFOC: Graphics for Spherical Distributions and Earthquake Focal Mechanisms

## Description

calculate the radiation patterns for SH waves

## Usage

 `1` ```radSH(del, phiS, lam, ichi, phi) ```

## Arguments

 `del` degrees, angle `phiS` degrees,angle `lam` degrees, angle `ichi` degrees, take off angle `phi` degrees, take off azimuth

## Details

Given a focal mechanism strike-dip-rake and a given incident angle (take-off angle) and azimuth, return the SH amplitude

## Value

Amplitude of the SH wave

## Author(s)

Jonathan M. Lees <jonathan.lees@unc.edu>

## References

K.~Aki and P.~G. Richards.Quantitative seismology. University Science Books, Sausalito, Calif., 2nd edition, 2002.

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21``` ```phiS=65 del=25 lam=13 x = seq(-1, 1, 0.01) y = x X = matrix(rep(x, length(y)), nrow= length(x)) Y = t(X) RAD2DEG = 180/pi p = RAD2DEG*(pi/2 -atan2(Y, X)) p[p<0] = p[p<0] + 360 R = sqrt(X^2+Y^2) R[R>1] = NaN dip =RAD2DEG*2*asin(R/sqrt(2)) ### Calculate the radiation pattern G = radSH(del, phiS, lam, dip, p) ### plot values image(x,y,G, asp=1) ```