To get started, select MATLAB Help or Demos from the Help menu. >> K1=1000*[1 -1;-1 1] K1 = 1000 -1000 -1000 1000 >> A1=[1 zeros(1,3);0 1 zeros(1,2)] A1 = 1 0 0 0 0 1 0 0 >> GK1=A1'*K1*A1 GK1 = 1000 -1000 0 0 -1000 1000 0 0 0 0 0 0 0 0 0 0 >> K2=500*[1 -1;-1 1] K2 = 500 -500 -500 500 >> A2=[0 1 0 0;0 0 1 0] A2 = 0 1 0 0 0 0 1 0 >> A2=[1 zeros(1,3);0 0 1 0] A2 = 1 0 0 0 0 0 1 0 >> GK2=A2'*K2*A2 GK2 = 500 0 -500 0 0 0 0 0 -500 0 500 0 0 0 0 0 >> K3=3000*[1 -1;-1 1] K3 = 3000 -3000 -3000 3000 >> A3=[0 1 0 0;0 0 1 0] A3 = 0 1 0 0 0 0 1 0 >> GK3=A3'*K3*A3 GK3 = 0 0 0 0 0 3000 -3000 0 0 -3000 3000 0 0 0 0 0 >> K4=2000*[1 -1;-1 1] K4 = 2000 -2000 -2000 2000 >> A4=[0 0 1 0;0 0 0 1] A4 = 0 0 1 0 0 0 0 1 >> GK4=A4'*K4*A4 GK4 = 0 0 0 0 0 0 0 0 0 0 2000 -2000 0 0 -2000 2000 >> K5=500*[1 -1;-1 1] K5 = 500 -500 -500 500 >> A5=[1 zeros(1,3);zeros(1,3) 1] A5 = 1 0 0 0 0 0 0 1 >> GK5=A5'*K5*A5 GK5 = 500 0 0 -500 0 0 0 0 0 0 0 0 -500 0 0 500 >> K6=6000*[ 1 -1;-1 1] K6 = 6000 -6000 -6000 6000 >> A6=[1 zeros(1,3);0 0 1 0] A6 = 1 0 0 0 0 0 1 0 >> GK6=A6'*K6*A6 GK6 = 6000 0 -6000 0 0 0 0 0 -6000 0 6000 0 0 0 0 0 >> GK=GK1+GK2+GK3+GK4+GK5+GK6 GK = 8000 -1000 -6500 -500 -1000 4000 -3000 0 -6500 -3000 11500 -2000 -500 0 -2000 2500 >> SubGK=[GK(2:4,2:4)] SubGK = 4000 -3000 0 -3000 11500 -2000 0 -2000 2500 >> F=[2000;-1000;5000] F = 2000 -1000 5000 >> Dis=SubGK\F Dis = 0.9412 0.5882 2.4706 >> D=[0;Dis(1:3,1)] D = 0 0.9412 0.5882 2.4706 >> Force=GK*D Force = 1.0e+003 * -6.0000 2.0000 -1.0000 5.0000 >> pushk3=GK3*D pushk3 = 1.0e+003 * 0 1.0588 -1.0588 0