spline.m

用MATLAB编写关于飞机设计的matlab程序

  
%
%	***  Input number of data points as N ***
%	***  input independent(独立变量) variable points as F(1,i) ***
%	***  input dependent（非独立变量） variable points as F(2,i) ***
%	***  subroutine returns spline coefficients in
%	     matriX F, the function is of the form:
%
%*************  S(di) = F(2,i)+F(3,i)*di+F(4,i)*di^2+F(5,i)*di^3 **************
%
%	     where di = X(i+1) - X(i)  ****???(不确定)
%
%      F(1:11,1:11)             % Real F(0:10,0:10)
%                               % Integer N
%
    
    
      for I = 1:N               % Do 5 I = 0,N-1
          F(6,I) = F(1,I+1) - F(1,I);
      end                       % 5     Continue
      F(3,1) = 0.0;
      F(4,1) = 1.0;
      F(5,1) = 0.0;
      for I = 2:N        %Do 6 I = 1,N-1
         F(4,I) = 2.0*(F(6,I-1) + F(6,I)) - F(5,I-1)*F(6,I-1);           %F(3,I) = 2.0*(F(5,I-1) + F(5,I)) - F(4,I-1)*F(5,I-1)
         F(3,I) = (3.0*((F(2,I+1)-F(2,I))/F(6,I) - (F(2,I) -F(2,I-1))/F(6,I-1))-F(6,I-1)*F(3,I-1))/F(4,I);%F(2,I) = (3.0*((F(1,I+1)-F(1,I))/F(5,I) - (F(1,I) -
                                                       %&   F(1,I-1))/F(5,I-1))-F(5,I-1)*F(2,I-1))/F(3,I)
         F(5,I) = F(6,I)/F(4,I);                       %F(4,I) = F(5,I)/F(3,I)
      end                %6     Continue
      F(4,N+1) = 0.0;    %F(3,N) = 0.0
      for I = N:-1:1     %Do 7 I = N-1,0,-1
          F(4,I) = F(3,I) - F(4,I+1)*F(5,I);           %F(3,I) = F(2,I) - F(3,I+1)*F(4,I)
          F(3,I) = (F(2,I+1) - F(2,I))/F(6,I) - (F(4,I+1) +2.0*F(4,I))*F(6,I)/3.0; %F(2,I) = (F(1,I+1) - F(1,I))/F(5,I) - (F(3,I+1) + 
                                                                                   %*           2.0*F(3,I))*F(5,I)/3.0
          F(5,I) = (F(4,I+1) - F(4,I))/(3.0*F(6,I));                               %F(4,I) = (F(3,I+1) - F(3,I))/(3.0*F(5,I))
      end                %7     Continue
%      Return