splitdrift

SPLITDRIFT inserts an element into a drift space

 SPLITDRIFT(DRIFTPOS, SPLIT) inserts a marker (zero-length) element
   at distance SPLIT ( 0 < SPLIT < 1) into a drift space 
   located at DRIFTPOS in THERING
 
 SPLITDRIFT(DRIFTPOS, SPLIT, ELEMSTRUCCTURE) inserts a marker (zero-length) element
   at distance SPLIT ( 0 < SPLIT < 1) into a drift space 
   located at DRIFTPOS in THERING
 
 Number of elements in the RING is thus increased by 2
 SPLIT (controls the position of the split 
 L1 = L0*SPLIT
 L2 = L0(1-SPLIT)
  where L0 is the length of the original DRIFT
   
 See also: MERGEDRIFT

0001 function splitdrift(DRIFTPOS, SPLIT, varargin) 
0002 %SPLITDRIFT inserts an element into a drift space
0003 %
0004 % SPLITDRIFT(DRIFTPOS, SPLIT) inserts a marker (zero-length) element
0005 %   at distance SPLIT ( 0 < SPLIT < 1) into a drift space
0006 %   located at DRIFTPOS in THERING
0007 %
0008 % SPLITDRIFT(DRIFTPOS, SPLIT, ELEMSTRUCCTURE) inserts a marker (zero-length) element
0009 %   at distance SPLIT ( 0 < SPLIT < 1) into a drift space
0010 %   located at DRIFTPOS in THERING
0011 %
0012 % Number of elements in the RING is thus increased by 2
0013 % SPLIT (controls the position of the split
0014 % L1 = L0*SPLIT
0015 % L2 = L0(1-SPLIT)
0016 %  where L0 is the length of the original DRIFT
0017 %
0018 % See also: MERGEDRIFT
0019  
0020 global THERING
0021 
0022 N0 = length(THERING); % number of elements in THERING before split
0023 
0024 L0 = THERING{DRIFTPOS}.Length;
0025 if (SPLIT < 0 | SPLIT >1)
0026     error('Second argument must be (0..1)');
0027 else    
0028     if nargin == 2
0029         for i = reverse(DRIFTPOS:N0)
0030             THERING{i+2} = THERING{i};
0031         end
0032         THERING{DRIFTPOS}.Length = L0*SPLIT;
0033         THERING{DRIFTPOS+2}.Length = L0*(1-SPLIT);
0034         THERING{DRIFTPOS+1} = struct('FamName','TEMPSPLIT', 'Length', 0, 'PassMethod','IdentityPass');
0035     elseif isstruct(varargin{1})
0036          % Check if a new element will fit
0037         if L0*(1-SPLIT) >= varargin{1}.Length
0038             for i = reverse(DRIFTPOS:N0)
0039                 THERING{i+2} = THERING{i};
0040             end
0041             THERING{DRIFTPOS}.Length = L0*SPLIT;
0042             THERING{DRIFTPOS+2}.Length = L0*(1-SPLIT)-varargin{1}.Length;
0043             THERING{DRIFTPOS+1} = varargin{1};
0044         else
0045             error('The inserted element is too long');
0046         end
0047     end
0048 
0049 end