time series analysis - correlation

My task involves finding the correlation between different variables for example air temperature and water temperature. The correlation can easily be calculated with the corrcoef command. However, when reading text books concerning time series analysis, they mention fitting models to the data to see if fluctuations in one variable i.e. temperature will affect the other (water temperature). I am rather overwhelmed by the amount of information provided in the literature, and dont really know where to start. Could anyone point me in the right direction of what I should be looking at doing first! Thanks in advance.

Answer 1

[tang]

Hi lestyn, Firstly,i'm so sorry that my english is poor that i am not sure to fully express my idea to you,anyway,i can try. Generally,if we want to know about the correlation between two seriess,we can draw the scatterplot chart first,then we should search for which model can fit the data best,well,some common models you should know,such as linear model,exp model,log-log model and so on.Accomplish these,some tatistics tests is a must,include t,F .etc MATLAB has a Statistics toolbox ,it can easily solve your problem. Some command you may use:scatter,regress . If you have any other problems,you can email it to me,my email is:[e-mail] best regards.

Answer 2

[Rajiv Singh]

If there is dynamic/causal dependence, you should try dynamic model fitting tools like those in System Identification Toolbox. See, ARX function for example.