1
$\begingroup$

I am analysing polymorphisms distribution data from Next Generation Sequencing data using Kernel density estimation (KDE).

However I would like to know if this method permit an unbiased comparisons, i.e.: Does KDE normalise the distribution?

The literature about this is scarce.

$\endgroup$
1
  • 2
    $\begingroup$ No. There is unlikely to be literature on this because there is almost nothing to say. Kernel density estimates are smoothings of the data, and broadly speaking if a distribution is skewed or long-tailed or whatever then the kernel density estimate will be similar. Regardless of what you mean by normalise or standardise, doing that before a kernel density estimate would be a separate step and kernel density estimation doesn't do it. $\endgroup$
    – Nick Cox
    Commented Mar 24, 2021 at 12:01

1 Answer 1

1
$\begingroup$

Kernel density estimates are smoothings of the probability distribution. Broadly speaking, if a distribution is skewed or long-tailed or whatever, then the kernel density estimate will be similar.

Regardless of what you mean by normalise or standardise, doing that before a kernel density estimate would be a separate step; and kernel density estimation doesn't do it.

On the latter, many meanings of normalise and standardise boil down to linear scalings, say that the data now lie in $[0, 1]$ or have mean $0$ and SD $1$. Such linear scalings don't change the shape of the distribution. On the other hand, non-linear transformations such as square roots or logarithms will change the shape of the distribution.

$\endgroup$
1
  • $\begingroup$ Thank you so much. It was very helpful your answer and It cleared me the idea about KDE $\endgroup$ Commented Mar 24, 2021 at 15:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.