# Within-cow Effects by Period

tmpar <- par( mar=c(3,3,0,0), mfcol=c(1,3) )

ylabs <- c("dry matter intake (DMI)","","")
xlabs <- c("(a) early period","(b) middle period","(c) late period")
names( xlabs ) <- names( ylabs ) <- levels( forage$per )
yaxis <- seq( 14, 22 )

tmp1 <- forage
tmp1$ally <- forage.mean+forage.spint
ylim <- log10( c(15,21.5) )

for ( i in levels( forage$per ) ) {
   tmpfor <- tmp1[forage$per==i, ]
   lsm <- list( se=std.dev( forage.fit$Within ) / sqrt(
      sample.size( forage.fit$cow, tmpfor, c("trt","hc") ) ) )
   attach( tmpfor )
   tmpc <- ci.plot( trt, ally, hc, ci=ci.width( forage.fit$Within, lsm=lsm ),
      ylim=ylim, type="b", xlab="", ylab="", yaxt="n" )
   detach( )
   mtext( xlabs[i], 1, 2 )
   mtext( ylabs[i], 2, 2 )
   axis( 2, log10( yaxis ), yaxis )
   abline( h=forage.mean, lty=3 )
}

rm( xlabs, ylabs, ylim, tmpfor, tmp1 )

par( tmpar )