samplefreq=100;

tstep=1/samplefreq;
t1=0:tstep:0.5-tstep;
t2=0.5+tstep:tstep:1.0-tstep;
t=[t1 t2];
n=length(t);
x=[sin(4*2*pi*t1) sin(9*pi*2*t2)];