| salinity {SMPracticals} | 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
data(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.
Examples
data(salinity)
## maybe str(salinity) ; plot(salinity) ...