salinity                package:boot                R Documentation

Water Salinity and River Discharge

Description:

     The 'salinity' data frame has 28 rows and 4 columns.

     Biweekly averages of the water salinity and river discharge in
     Pamlico Sound, North Carolina were recorded between the years 1972
     and 1977. The data in this set consists only of those measurements
     in March, April and May.

Usage:

     salinity

Format:

     This data frame contains the following columns:


     'sal' The average salinity of the water over two weeks.

     'lag' The average salinity of the water lagged two weeks.  Since
          only spring is used, the value of 'lag' is not always equal
          to the previous value of 'sal'.

     'trend' A factor indicating in which of the 6 biweekly periods
          between March and May, the observations were taken. The
          levels of the factor are from 0 to 5 with 0 being the first
          two weeks in March.

     'dis' The amount of river discharge during the two weeks for which
          'sal' is the average salinity.

Source:

     The data were obtained from

     Ruppert, D. and Carroll, R.J. (1980) Trimmed least squares
     estimation in the  linear model.  _Journal of the American
     Statistical Association_, *75*, 828-838.

References:

     Davison, A.C. and Hinkley, D.V. (1997)  _Bootstrap Methods and
     Their Application_. Cambridge University Press.

