Problem with data precision while generating square wave.

I used square(2*pi*f*t) to generate a square wave.

I set f to 1000 and t=0:Ts:0.05

Ts=1.000000000000000e-05

when i type square(2*pi*1000*0.020500000000000) in command window, answer is +1 and for square(2*pi*1000*0.020510000000000) answer is -1

But when i run a program with the expression square(2*pi*f*t), even for square(2*pi*1000*0.020510000000000) , i am getting +1.

How to fix this???

Answer 1

[Mathieu NOE]

hi

my suggestion

f = 1000 ;
Ts=1e-05;
t=0:Ts:0.05;

angl = 2*pi*(mod(f*t,1));
square_wav = 0.5*(sign(sin(angl))+1);

plot(t,angl);

plot(t,square_wav);