# How to deal with non random data in statistical analysis?

I have a set of monthly water quality data, and I want to use them in a few statistical analysis (such as finding distribution or using in copula models) which require random variables as input. I performed RUN TEST for randomness (runstest function in MATLAB) but the result showed that the data is not from a random data set. I tried removing seasonality from the data but it is still non random. Is there any way to transform or convert this data to a random data set so I acn use it in may analysis? Thank you

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If you kill all of the signal first, then what on earth do you hope to learn from the eventual analysis? –  Henning Makholm Dec 30 '12 at 21:04
@HenningMakholm I don't want to kill all the signals, but I have been told that my data doesn't meet the requirement of the copula model's input (being a random variable). Also, somebody mentioned that I should do something about separating independent and time dependent parts. I but I don't know how to do it? –  Fred Dec 30 '12 at 21:18

You data $X$ are indexed by time $t$, so the runs test is a nonparametric test confirming autocorrelation in your data.