MomentDist: Distance Between Moment Tensors

In RFOC: Graphics for Spherical Distributions and Earthquake Focal Mechanisms

Distance Between Moment Tensors

Description

Calculate the distance between moment tensors based on quaternions.

Usage

MomentDist(E1, E2)

Arguments

E1	Moment tensor
E2	Moment tensor

Details

Moment tensors should be right handed.

Value

angle in degrees

Author(s)

Jonathan M. Lees<[e-mail]>

References

Tape and Tape, 2012

See Also

forcerighthand, testrightHAND

Examples

Mtens = c(-0.412, 0.084, 0.328 ,0.398, -1.239, 1.058)
M1 = matrix(c(Mtens[1], Mtens[4], Mtens[5], Mtens[4], Mtens[2],
Mtens[6], Mtens[5],Mtens[6], Mtens[3]), ncol=3, nrow=3, byrow=TRUE)



Mtens = c(5.054, -2.235, -2.819, -0.476, 5.420, 5.594)
M2 = matrix(c(Mtens[1], Mtens[4], Mtens[5], Mtens[4], Mtens[2],
Mtens[6], Mtens[5],Mtens[6], Mtens[3]), ncol=3, nrow=3, byrow=TRUE)

E1 = eigen(M1)

###  make sure these are a right handed system,
###   ie x1 cross x2 = x3


E2 = eigen(M2)

###  make sure these are a right handed system,
###   ie x1 cross x2 = x3
testrightHAND(E1$vectors) 
testrightHAND(E2$vectors) 

E1$vectors = forcerighthand(E1$vectors)

E2$vectors = forcerighthand(E2$vectors)


testrightHAND(E1$vectors) 
testrightHAND(E2$vectors) 

MomentDist(E1, E2)

RFOC documentation built on Sept. 8, 2023, 6:12 p.m.