w3.m

来自「这是一个模拟第3类模式地震波的matlab脚本。 This a collect」· M 代码 · 共 32 行

%W3.m	Non-dimensional function W_{III} in mode III velocity kernel
%	= 1- Integral of C_{III} 
%	The integration is done numerically using the trapezoidal rule
% See also C3.m
function WIII = W3(ARG)

  N = length(ARG);  % number of evaluation points
  nsub = 20; % number of sub-intervals for numerical integration
  nsub = max(nsub, nsub*(ARG(2)-ARG(1))/2/pi );
  Psub = nsub+1;

  if ARG(1)==0, error('FATAL ERROR in W3: ARG1 must be > 0'), end

 % first value, 
 % use same 'nsub' because usually ARG(1) = delay =~ ARG_step
  dsub = ARG(1)/nsub ;
  arg = (0:nsub).'*dsub ;
  CIII(1) = 0.5 ;  % = C3(0)
  CIII(2:Psub) = C3(arg(2:Psub)) ;
  WIII(1) = dsub*(0.5*CIII(1) + sum(CIII(2:nsub)) + 0.5*CIII(Psub) );

 % remaining values
  for i = 2:N
    dsub = (ARG(i)-ARG(i-1))/nsub ;
    arg  = ARG(i-1) + dsub*(0:nsub).' ;
    CIII = C3(arg) ;
    WIII(i) = WIII(i-1) ...
      + dsub*(0.5*CIII(1) + sum(CIII(2:nsub)) + 0.5*CIII(Psub) );
  end  

  WIII = 1 - WIII(:) ;