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...h line (through some data gaps) from which phenological type indices of snow depth can be derived. What are you trying to do find the dominant periodicy? make a prediction equation? fit a smooth line? or... give us some more information and maybe we can help On 1/28/08, Carson Farmer [1]<cfarmer at uvic.ca> wrote: Rolf Turner wrote: On 26/01/2008, at 10:54 AM, Carson Farmer wrote: Dear List, I am attempting to perform a harmonic analysis on a time series of snow depth, in which the annual curve is essentially asymmetric (i.e. snow accumulates slowly over time, and the subsequent...

Dear List, I am looking for an efficient method for replacing values in a data.frame conditional on the values of a separate data.frame. Here is my scenario: I have a data.frame (A) with say 1000 columns, and 365 rows. Each cell in the data.frame has either valid value, or NA. I have an additional data.frame (B) with the same number of rows and columns, with valid values in all cells. What I

Hello R community, Does anyone know of a package that will perform cycle regression analysis? I have searched the R-help archives etc. but have come up with nothing so far. If I am unable to find an existing R package to do so, is there anyone familiar with fitting sine functions to data. My problem is this: I have a long time-series of daily SWE estimates (SWE = snow water equivalence, or

Hello List, Is there a faster way to set values in one data.frame equal to NA conditional on the corresponding value in another data.frame? Currently I am using: > b[is.na(a)] <- NA where 'a' and 'b' are data.frames of equal size/dimensions, and 'a' contains NAs but 'b' does not. This is extremely slow as is, as my data.frames are about 6000 columns by

Dear List, I am attempting to perform a harmonic analysis on a time series of snow depth, in which the annual curve is essentially asymmetric (i.e. snow accumulates slowly over time, and the subsequent melt occurs relatively rapidly). I am trying to fit a curve to the data, however, the actual frequency is unknown. I have been trying to follow the methods in Peter Bloomfields text