Fourier series example problem

[ttokoro]

[CornelBejan]

The Nt seems to be the number of harmonics, if I am not misinterpreting it.
Why for the first harmonic Nt should be 2? 
Nt shouldn't it be 1 for the first harmonic?
The image above shows the first harmonic and for that Nt needs to be equal with 2.

[LucMeekes]

Your sheet calculates the first two harmonics of the signal.

BUT, the Fourier sequence of a square wave only contains odd harmonics. So from the first 2 harmonics only the first is (and should be !) visible. The second harmonic is zero.

If you set Nt:=3 I suspect that you should see the result of first and third harmonics added.

Success!

Luc

[CornelBejan]

I know that the square wave signal has only the odd harmonics, but the first harmonic is the first harmonic, and it is odd:).

What it's your opinion about this sequence?

[LucMeekes]

My conclusion: There's a     2    missing in each of the sin()  and cos() arguments of the Fourier functions that you are using.

The correct function to create a sine of frequency F is not sin( pi * F * t)  but  sin(2 * pi * F * t).

Now your n has to step twice as much paces to run past all harmonics.

Success!

Luc