function [res] = SQ(L,XX,YY,J1,J2,I,I1,I2,A,B,C) % This function is used by Finite Element Method % (Algorithm 12.5) to evaluate line integrals % using Composite Simpson's Method. syms('X1', 'Y1', 'X2', 'Y2', 'H', 'T1', 'T2', 'T3'); syms('K', 'X', 'Q3', 'Q1', 'Q2', 'SSQ', 'S'); S = zeros(1,101); X1 = XX(J1); Y1 = YY(J1); X2 = XX(J2); Y2 = YY(J2); H = 0.01; T1 = X2-X1; T2 = Y2-Y1; T3 = sqrt(T1*T1+T2*T2); for K = 1 : 101 X = (K-1)*H; if L == 1 S(K) = T3*GG1(T1*X+X1,T2*X+Y1,A,B,C,I,I1,I2); end; if L == 2 S(K) = T3*GG2(T1*X+X1,T2*X+Y1,A,B,C,I,I1); end; if L == 3 S(K) = T3*GG3(T1*X+X1,T2*X+Y1,A,B,C,I,I2); end; if L == 4 S(K) = T3*GG4(T1*X+X1,T2*X+Y1,A,B,C,I,I1); end; if L == 5 S(K) = T3*GG5(T1*X+X1,T2*X+Y1,A,B,C,I,I2); end; end; Q3 = S(1)+S(101); Q1 = 0; Q2 = S(100); for K = 1 : 49 Q1 = Q1+S(2*K+1); Q2 = Q2+S(2*K); end; SSQ = (Q3+2*Q1+4*Q2)*H/3; res = SSQ;