Hi Anto, could you tell us a bit more? I'd love to help but don't think I have enough info.
Reading your post there are two things you could perhaps adress to make sure we're on the same page:
- A time series object is a distinct and separate thing from something that can be plotted as a time series (in a much broader sense of the word). The error you refer to is saying that what you're feeding it is in fact not a time series object (an object with class "ts" or "xts").
- What you posted is not an error message but a warning message. So what you're trying to accomplish should likely be able to run with just a warning message. So that's likely not where the problem lies.
Can you give an example of your code so we can reproduce your error & warning and see how we can help?