MATLAB: How to generate variable sine wave after fixed number of samples

Question

i have to generate a sine wave increasing its frequency about 50khz after certain periods(like it should generate 25 periods of 50 khz and 25 periods of 100khz and go on…) until 1Mhz. Thanks in Advance

Answer 1

np=25
f=50
t=0:T/10:T;
y=sin(2*pi*f*t);
for k=1:19
  f=f+50;
  T=1/f;
  t1=t(end)+T/20:T/20:t(end)+np*T;
  y1=sin(2*pi*f*t1);
  t=[t t1];
  y=[y y1];
end
plot(t,y)