Which analysis method is the best option to analysis two signals?

Hello,

I am working with two different Heart rate (BPM) vectors. Let's Say Vector A and Vector B.

Vector A is my Benchmark, it has more samples in a period of time (60 seconds) Vector B is the signal that I want to Analyse and compared with Vector A; It has less samples, but through the use the function to search the nearest neighbor, the Vector B have now the same lenght that vector A.

I am struggling now about which method to use to analyse the signal. My Aim and focus is to calculated the error between B, depending of A. I was thinking through the use of Probability distribution and lineal regresion but i am not that sure.

I will like to read may be another ideas, someone that have more experiences in signals analysis.

Thanks in advances, i will be looking forward to your answer

Larissa