function varargout=get_DR_corrs(opCode,energy,varargin)

%

% KL=get_DR_corrs(1,energy,Icorr,fflag);

%

% Compute DR corrector kicks (KL=BL/brho) from currents

%

% Icorr=get_DR_corrs(2,energy,KL,fflag);

%

% Compute DR corrector currents (KL=BL/brho) from kicks

%

% INPUTs (opCode=1):

%

%   opCode = 1 (I to KL conversion)

%   energy = DR energy (GeV) [scalar]

%   Icorr  = DR corrector currents (amps) [101 element array]

%   fflag  = (optional) if present and nonzero, fudge factors will be used

%

% INPUTs (opCode=2):

%

%   opCode = 2 (KL to I conversion)

%   energy = DR energy (GeV) [scalar]

%   KL     = corrector kicks (radians) [101 element array]

%   fflag  = (optional) if present and nonzero, fudge factors will be used

%

% The order of correctorss in the Icorr or KL arrays must be:

%

%    ZH1R,...,ZH14R,ZH16R,...,ZH48R (ZH15R is missing)

%    ZV1R,...,ZV15R,ZV17R,...,ZV51R (ZV16R is missing)

%    ZH100R,ZH101R,ZH102R,ZV100R (specials)

%

% OUTPUT (opCode=1):

%

%   KL    = DR corrector kicks (radians; same signs as Icorr)

%            [101 element array, same order as Icorr]

%

% OUTPUT (opCode=2):

%

%   Icorr = DR corrector currents (amps; same signs as KL)

%            [101 element array, same order as KL]



% ==============================================================================

% 22-FEB-2009, M. Woodley

%    Do either I-to-KL and KL-to-I conversion

% ==============================================================================



Ncorr=101;



% check input args



if (~exist('opCode','var'))

  error('opCode argument not supplied')

end

if (~exist('energy','var'))

  error('energy argument not supplied')

else

  if (energy<=0)

    error('Bad energy value')

  end

end

if (opCode==1)

  if (nargin<3)

    error('At least 3 input arguments required for opCode=1')

  end

  Icorr=varargin{1};

  if (length(Icorr)~=Ncorr)

    error('Incorrect Icorr length')

  end

elseif (opCode==2)

  if (nargin<3)

    error('At least 3 input arguments required for opCode=2')

  end

  KL=varargin{1};

  if (length(KL)~=Ncorr)

    error('Incorrect KL length')

  end

else

  error('Invalid opCode')

end

if (nargin>3)

  fflag=varargin{2};

else

  fflag=0;

end

fudge=(fflag~=0);



% ==============================================================================

% DR CORRECTOR MAGNET DATA

% ==============================================================================



% there are 6 types of DR corrector:



%    1 = NKK type CH (horizontal)

%    2 = Tecno model 58283 (horizontal)

%    3 = NKK type CV (vertical)

%    4 = Tecno model 58928 (vertical)

%    5 = Tecno model 58284 (vertical)

%    6 = Tecno model 82982 (horizontal)

%    7 = Tecno model 82983 (horizontal)

%    8 = ZV100R (vertical; modified)



% B vs I slopes and effective lengths

% (from: ATF$MAG:MAG_KI_Z_NKK_CH.FOR

%        ATF$MAG:MAG_KI_Z_TECNO_H58283.FOR

%        ATF$MAG:MAG_KI_Z_NKK_CV.FOR

%        ATF$MAG:MAG_KI_Z_TECNO_V58928.FOR

%        ATF$MAG:MAG_KI_Z_TECNO_V58284.FOR

%        ATF$MAG:MAG_KI_Z_TECNO_ZH82982.FOR

%        ATF$MAG:MAG_KI_Z_TECNO_ZH82983.FOR

%        ATF$MAG:MAG_KI_ZV100R.FOR)



cbvi=[108.0e-4;102.8e-4;112.0e-4;111.5e-4;102.0e-4;12.5e-3;5.9e-3;8.5e-3]; % T/amp

cleff=[0.11921;0.11455;0.1248;0.128141;0.172;0.24955;0.1679;0.13874];      % m



% corrector types

% (from: ATF$MAG:MAG_KI_MAIN.FOR)



ctype=[ ...

  1;1;1;1;1;1;1;1;1;2;2;2;2;2;  1;1;1;1;1;1;1;1;1;1; ... %ZH1-25

  1;1;1;1;1;1;1;1;2;2;2;2;2;2;1;1;1;1;1;1;1;1;1; ...     %ZH26-48

  3;3;3;3;3;3;3;3;3;4;4;4;4;4;5;  3;3;3;3;3;3;3;3;3; ... %ZV1-25

  3;3;3;3;3;3;3;3;5;5;5;4;4;4;4;4;5;3;3;3;3;3;3;3;3; ... %ZV26-50

  3; ...                                                 %ZV51

  6;7;3;8];                                              %ZH100-102,ZV100



% "Kubo" fudge factors

% (none available)



cfudge=zeros(Ncorr,1);



% ==============================================================================



% compute rigidity



Cb=1e10/2.99792458e8; % kG-m/GeV

brho=Cb*energy;



% perform requested conversion



if (opCode==1)

  

% convert current to KL

  

  KL=zeros(Ncorr,1);

  for n=1:Ncorr

    t=ctype(n);

    B=Icorr(n)*cbvi(t); % T

    KL(n)=(10*B)*cleff(t)/brho; % radian

    if (fudge),KL(n)=KL(n)/(1+cfudge(t));end

  end

  varargout{1}=KL;

else

  

% convert current to KL

  

  Icorr=zeros(Ncorr,1);

  for n=1:Ncorr

    t=ctype(n);

    B=0.1*brho*KL(n)/cleff(t); % T

    if (fudge),B=B*(1+cfudge(t));end

    Icorr(n)=B/cbvi(t); % amps

  end

  varargout{1}=Icorr;

end



end