Post by pioco on Jul 30, 2003 6:47:16 GMT -5
I think that I went out from the road in the previous mail but now I think I solved the situation. In this part I found different mistakes, some really strange. on the sixth page exp(-jwt) is equal to cos(wt)-jsin(wt); on page 11 f=dphi/dt is wrong because the derivative of the phase is the angular velocity and we need to divide for 2*pi. On page 14 the equation 8 is wrong: the second term in the summation as a minus therefore ....-1/2(qn+ibn)exp(-jnwt). so also equation 10b needs to have a minus. On page 15 there is somethin strange. I think I solved the problem or I didn' understand anything: Cn=An+JBn where does it come from. For me It's wrong and the modulus of Cn equals the one of An or Bn(see also 10 and 10b the modulus are equal). to me it is obvious because 15 is simply a shorter form of 14 possible because modulus of Cn equals modulus of C(-n). This brings to page 21 in which the words are correct and mathematics is wrong. say that Cn=sqrt(sqr(An)+sqr(Bn)) is in contradiction with Cn=An+jBn of page 15. so I thought at a simple mistake like modulus forgotten. But it can't be because than the expression is mathematically wrong because An and Bn are complex numbers. and even if you evaluate correctly the modulus of Cn starting from An+jBn you will not reach the results that two-sided spectrum amplitudes are half of one-sided. While if you tike simply the modulus of An or Bn it is directly demonstrated.then in power everythings works because you have 2*sqr(0.29)+2*sqr(0.54)+2*sqr(0.18)and this is equal to half of summation of the suares of the single sided spectrum as all the books say. I would like that the author of this site can answer to this remarks just to know if I'm wright or not before going on other tutorials.
