Talk:Constant-Q transform

In my opinion at least, I think the page looks a little rough could do with some better formatting... But right now it's 4am, I need sleep, and I'll be working on my project for a bit :-(

Intelmole 04:04, 15 March 2007 (UTC)[reply]

i am not shure about "j" in exp function, what is it? —Preceding unsigned comment added by 77.184.102.91 (talk) 20:49, 11 November 2007 (UTC)[reply]

Apologies for my electronic engineering nature, j = i = sqrt (-1) Intelmole (talk) 23:28, 28 January 2008 (UTC)[reply]

S is not defined

Can we add a definition for S?

Problems with essentials in this page...

I came to this page to learn something about the Constant Q transform, at least to see its essential definition.

The section Constant_Q_transform#Calculation_of_the_Transform is already in trouble at these statements.

Q={\frac {f_{k}}{\delta f_{k}}}

Window length for the k-th bin

N[k]=\left({\frac {f_{s}}{\delta f_{k}}}\right)=\left({\frac {S}{f_{k}}}\right)Q

As S/f_k is the number of samples processed per cycle at frequency f_k,

It is unavoidable that $S=f_{s}$ . And somewhere $f_{k}$ must be defined in terms of $k$ . I cannot see that it is. Then we can define $N[k]$ . And a floor function will be needed, I think.

I am certain that the mathematics presented in this section are flawed and I think the reason is some lack of rigor. I'll have to find out the definition from somewhere else and fix the math here. I'm pretty sure I can and have surmised the definition of the Constant Q Transform, but I will check with other sources before I fix the definition here. 70.109.188.75 (talk) 04:56, 3 June 2014 (UTC)[reply]

Thanks for your concern and willingness to help! Have you read the two papers by Judith Brown that are cited in the article? To the best of my knowledge they are the foundation of the transform this article is attempting to be about, and my guess is that there is no clearer statement of the transform anywhere in the literature. I don't doubt that there are problems with the math here, and I haven't systematically compared it to the papers myself yet. But we also don't know for sure that there aren't problems with the math in the original papers. Eflatmajor7th (talk) 22:09, 3 June 2014 (UTC)[reply]