The motor data frame has 94 rows and 4 columns. The rows are obtained by removing replicate values of time from the dataset mcycle. Two extra columns are added to allow for strata with a different residual variance in each stratum.

motor

Format

This data frame contains the following columns:

times

The time in milliseconds since impact.

accel

The recorded head acceleration (in g).

strata

A numeric column indicating to which of the three strata (numbered 1, 2 and 3) the observations belong.

v

An estimate of the residual variance for the observation. v is constant within the strata but a different estimate is used for each of the three strata.

Source

The data were obtained from

Silverman, B.W. (1985) Some aspects of the spline smoothing approach to non-parametric curve fitting. Journal of the Royal Statistical Society, B, 47, 1--52.

References

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

Venables, W.N. and Ripley, B.D. (1994) Modern Applied Statistics with S-Plus. Springer-Verlag.

See also

mcycle