calculating distances between DNA markers

Question

[milton.andy]

I am seeking help with what possibly is a trivial problem but so far I have not been able to locate suitable resource on the web so any pointers would be very appreciated. I have two uneven but sorted numerical arrays representing chromosomal positions of two non-overlaping sets of markers (SNPs). They can be represented as: [A1, A2, ..An] and [B1, B2,..Bz]. I need to automate calculation of differences between each member of set A and each member of set B:

A1 - B1, A1 - B2 ... A1 - Bz
A2 - B1, A2 - B2 ... A2 - Bz
..........................................
An - B1, An - B2 ... An - Bz

Output needs to be a sorted list of absolute values.

Given large numbers of markers involved I cannot imagine doing it manually. As I am not familiar with programming, bash or python script would be best.

If this has been already answered in the forum, please post a link. Many thanks, Andy

[finswimmer]

Hello milton.andy ,

• Could you please provide an example of how your input looks like exactly?

• Please use the formatting bar (especially the code option) to present your post better. I've done it for you this time.
  

Thank you!

[milton.andy]

Hi finswimmer, Thank you very much for your replay. A small example of the input can be found here:

https://drive.google.com/file/d/17DR6ZUtXP0jpGxf35E6PqAEERpNz7wpi/view?usp=sharing

The desired output should be as in this textfile: https://drive.google.com/file/d/1R_6duEybnIKn_3P9AI4ixPqlrzYcdI4l/view?usp=sharing

Being a novice I am having trouble conforming to some of the requirements, such as using the appropriate formatting conventions (aluded to in your second commet). I apologize for this and will try to learn these things in the near future.

Thanks again for your help Andy

[finswimmer]

Hello milton.andy ,

thanks for providing the example. Unfortunately this is not clear to me. Does the setA contain 3 Variants and the setB 6? Or is this a format issue?

The distances you show in your example output seems to be the absolute value for difference, otherwise A1-B1 would be negative. Am I right?

fin swimmer

[Joe]

What does the input data actually look like?

[milton.andy]

An example of the input can be found here:

https://drive.google.com/file/d/17DR6ZUtXP0jpGxf35E6PqAEERpNz7wpi/view?usp=sharing

The desired output should be as in this textfile: https://drive.google.com/file/d/1R_6duEybnIKn_3P9AI4ixPqlrzYcdI4l/view?usp=sharing

Thanks jrj.healey