### ECH_WAVECEN

Determine the central wavelength of the order

##### Description

Use a binary chop search to determine the order which corresponds to the given echelle gamma angle. Having determined the order, perform a similar search to determine the wavelength within the order which corresponds to the given echelle theta angle.

ECH_INIT must be called before calling this routine.

##### Invocation

CALLECH_WAVECEN (THETA, GAMMA, WC, MC, STATUS)

##### Arguments
 READ THETA REAL Echelle theta angle corresponding to the current configuration (radians) READ GAMMA REAL Echelle gamma angle corresponding to the current configuration (radians) WRITE WC REAL Central wavelength corresponding to the current configuration (ie that wavelength which lies within order M and is closest to that in the centre of the field) WRITE MC INTEGER Order number corresponding to the current configuration (the order closest to that in the centre of the field) READ, WRITE STATUS INTEGER Global status value

None known.

##### Authors

C.J. Hirst UCL (ZUVAD::CJH)