Again and again, this post for me is none other than the cry of my soul. I am struck by the fact that some things from everyday life used by us for granted. We believe even in lie. Take the formula, substitute the value and it works (so far, seems to be :). People, stop! “But all is working right!” – You might say. “Smart guy from the forum said that everything will work perfectly!”. Perhaps smart guy is right, but as the classic said “Do not trust anyone!”. Should you trust me? – It is really possible, but after rechecking. After all the task of the engineer not only to create something but also deeply understand the running process. As an example of “it should work!”, we will consider the recursive formula for the sine wave generation, which I have repeatedly seen on many websites and blogs dedicated to digital signal processing. Naturally, I checked this formula in practice and was really surprised by such simplicity. It really works! I was so amazed that could not resist and set out myself to understand the magic of the miracle formula. I was not very surprised when the clear and simple way of the formula deduction was not found in the network. Found a lot of absurdities, empirical and deductive methods and other “rubbish” but for myself – NOTHING. ↓ Read the rest of this entry…