# EV2Q: Convert from Euler Vectors to rotation Quaternions In RSpincalc: Conversion Between Attitude Representations of DCM, Euler Angles, Quaternions, and Euler Vectors

## Description

`EV2Q` converts from Euler Vectors (EV) to Quaternions (Q).

## Usage

 `1` ```EV2Q(EV, tol = 10 * .Machine\$double.eps, ichk = FALSE, ignoreAllChk = FALSE) ```

## Arguments

 `EV` Euler Vectors (EV) vector [m1, m2, m3, MU]. `tol` Tolerance from deviations from unity for the determinant of rotation matrices or the the vector length for unitary vectors. `ichk` Logical, FALSE=disables near-singularity warnings. `ignoreAllChk` Logical, TRUE=disables all warnings and error checks (use with caution!).

## Value

Quaternions (Q) vector [q1, q2, q3, q4].

Jose Gama

## References

by John Fuller, 14 Jul 2008 SpinCalc, Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors. http://www.mathworks.com/matlabcentral/fileexchange/20696-function-to-convert-between-dcm–euler-angles–quaternions–and-euler-vectors

Paolo de Leva, 01 May 2013 SpinConv, Conversion from a rotation representation type to another. http://www.mathworks.com/matlabcentral/fileexchange/41562-spinconv

`Q2EV`
 ```1 2 3``` ```EV <- c(-0.1995301, -0.8765382, -0.4380279, 114.4324 * (pi/180)) EV2Q(EV,1e-7) #EV2Q(EV) ```