Dear all,

I'm a newer to spatio-temporal analysis though I am quite familiar with
spatial one. When coming to spatio-temoral prediction using krigeST, I have
some queries as follows:

1. it seems that the krigeST can only deal with data with full layout
format (e.g., STFDF class), however our data in practice, which is often
the case, come with sparse format (e.g., STSDF class) because of different
No. of samples in each time point or missing values. Under this
circumstance, I mean only with STSDF class, what I can do if I still want
to make spatio-temporal prediction? just sort out a  STFDF format from the
available data? or else

2. I happened to see a replying email by Edzer to someone which said
krigeST was designed to exploit separaility of spatio-temporal covariance
models. If this is the case, what dose other types of spatio-temporal
variogram (e.g., productSum, sumMetric, and simpleSumMetric) mean? Do them
predict with a jiont spatio-temporal covariance? if so, why one needs to
specify purely spatial and temporal variogram if the jiont spatio-temporal
covariance is specified?

3. In terms of specification of arguments in vgmST, it seems to be too
subjective to specify arguments for varigram of space and time, for
example, time = vgm(1, "Exp", 1.5 * 3600 * 24)). How could I know range,
sill, or nugget for the varigram?

Thanks very much.

With regards

Yi

	[[alternative HTML version deleted]]

