MASS - First distance missing

[albertasdvirnas]

• MASS version: 0.1.3
• Python version: 2.7
• Operating System: Ubuntu

Description

I was trying to compare two time series query=X and ts=XY, i.e. time series has identical beginnings

What I Did

I ran actual = mts.mass(ts, query)

I noticed that the algorithm doesn't return a score of query along the first position of ts. A hot fix seems to add some random number in front of ts

[tylerwmarrs]

@albertasdvirnas Thank you for submitting the issue. I am actually unable to reproduce the missing first distance with the MASS algorithm.

If you can provide some data to reproduce the issue, it would help me out a lot.

[albertasdvirnas]

ts = np.array([ 2, 1, 1, 4, 5])
query = np.array([2, 1, 1, 4])
actual = mts.mass(ts, query)

returns array([1.85113597]), while I expect it to return something like

array([0, 1.85113597]) ?

[tylerwmarrs]

Generally, MASS2 is the preferred algorithm over MASS. I simply implemented MASS to try to have a complete module. The original author's implementation of MASS has this same caveat.

If you have a solution to fix this, then feel free to make a contribution. The original MASS implementation is here:

https://www.cs.unm.edu/~mueen/findNN.html