pro d17_polcalc,main,ferro=ferro,phi,F1,F2,p1,p2

                LAMP procedure to calculate the inefficiencies of the polarizing elements based on a series of scans with different flipper states

                The corrections are based on the equations in:

                Wildes, Rev. Sci. Instrum., 70 (1999) 4241

NECESSARY VARIABLES:

                main=an array of eight numbers corresponding to the integrated intensities

                                measured for the main beam OR a reflection from a non-polarizing sample (e.g. silicon), with their errors.

                                The format of the numbers is as follows:

                                [I00,e(00),I10,e(10),I11,e(11),I01,e(01)]

OPTIONAL VARIABLES:

                ferro=an array of four numbers corresponding to the integrated intensities

                                measured for the reflection from a ferromagnetic sample, with their errors

                                The format of the numbers is as follows:

                                [I00,e(00),I10,e(10),I11,e(11),I01,e(01)]

 OUTPUTS:

                All the outputs are two component arrays, the first element is the value and the second is the error

                phi=a combination of the efficiencies of the polarizer and the analyser

                F1=the efficiency of the 1st flipper

                F2=the efficiency of the 2nd flipper

                p1=the efficiency of the polarizer      (can only be determined if ferro is included)

                p2=the efficiency of the analyser      (can only be determined if ferro is included)

                e.g. type at the LAMP interface

 d17_polcalc,[2206,10.2,20,2.1,2110,9.5,40,3.1],ferro=[1104,5.2,20,2.1,100,10.0,10,3.1],phi,F1,F2,p1,p2