<font face="trebuchet ms,sans-serif">Alguns cuidados você deve tomar com datas. Representá-las com string não vai reconhecer a ordem cronológica das medidas. É necessário converter para data. Segue um CMR sobre os dados fornecidos. Outras opções existes no pacote gplots, lattice, ggplot2.<br>
<br><span style="font-family:courier new,monospace">x <- c("30/04/2010","13/05/2010","28/05/2010",<br>       "15/06/2010","30/06/2010","15/07/2010",<br>       "30/07/2010","15/08/2010","30/08/2010",<br>
       "15/09/2010","30/09/2010","15/10/2010",<br>       "30/10/2010","15/11/2010","30/11/2010",<br>       "15/12/2010","30/12/2010","15/01/2011",<br>
       "30/01/2011","15/02/2011","28/02/2011",<br>       "15/03/2011","30/03/2011","15/04/2011",<br>       "30/04/2011","15/05/2011","30/05/2011",<br>
       "15/06/2011","30/06/2011","15/07/2011")<br><br>y <- c(0.278, 0.068, 0.064, 0.028, 0.030, 0.024, NA, 0.025,<br>       0.039, 0.077, 0.081, NA, 0.043, NA, 0.343, NA, 0.195,<br>       0.090, 0.027, 0.157, 0.122, 0.069, 0.197, 0.107, 0.103,<br>
       0.154,0.164, 0.051,0.243,0.145)<br><br>SDFE10 <- c(0.294,0.033,0.058,0.013,0.006,0.006,NA,0.018,0.031,0,0,<br>            NA,0.021,NA,0.435,NA,0.057,0.049,0.005,0.220,0.159,0.029,<br>            0.194,0.114,0.109,0.116,0.187,0,0.266,0.121)<br>
<br># colocar num data.frame, eliminar NA, converter para data<br>da <- data.frame(x=as.POSIXlt(x, format="%d/%m/%Y"), y=y, sd=SDFE10)<br>da <- na.omit(da)<br>da$x<br><br>plot(y~x, data=da, ylab=expression(Concentração~de~Ferro~na~solução~do~solo~(mg~L^{-1})),<br>
     xlab="Dia", pch=4, type="b", xaxt="n",<br>     ylim=c(-0.1,0.7))<br>with(da,<br>     arrows(x, y-sd, x, y+sd, code=3, angle=90,length=0.03))<br>#axis.POSIXct(side=1, at=da$x, format="%d/%m")<br>
axis.POSIXct(side=1, at=seq(min(da$x), max(da$x), by="month"), format="%d/%m")<br><br>require(gplots)<br>help(plotCI, help_type="html")<br><br></span>À disposição.<br>Walmes.<br><br clear="all">
</font><div><span style="font-family:trebuchet ms,sans-serif">==========================================================================</span><br style="font-family:trebuchet ms,sans-serif"><span style="font-family:trebuchet ms,sans-serif">Walmes Marques Zeviani</span><br style="font-family:trebuchet ms,sans-serif">
<span style="font-family:trebuchet ms,sans-serif">LEG (Laboratório de Estatística e Geoinformação, 25.450418 S, 49.231759 W)</span><br style="font-family:trebuchet ms,sans-serif"><span style="font-family:trebuchet ms,sans-serif">Departamento de Estatística - Universidade Federal do Paraná</span><br style="font-family:trebuchet ms,sans-serif">
<span style="font-family:trebuchet ms,sans-serif">fone: (+55) 41 3361 3573</span><br style="font-family:trebuchet ms,sans-serif"><span style="font-family:trebuchet ms,sans-serif">VoIP: (3361 3600) 1053 1173</span><br style="font-family:trebuchet ms,sans-serif">
<span style="font-family:trebuchet ms,sans-serif">e-mail: <a href="mailto:walmes@ufpr.br" target="_blank">walmes@ufpr.br</a><br>skype: walmeszeviani<br style="font-family:trebuchet ms,sans-serif"></span><span style="font-family:trebuchet ms,sans-serif">twitter: @walmeszeviani</span><br style="font-family:trebuchet ms,sans-serif">
<span style="font-family:trebuchet ms,sans-serif">homepage: <a href="http://www.leg.ufpr.br/%7Ewalmes" target="_blank">http://www.leg.ufpr.br/~walmes</a></span><br style="font-family:trebuchet ms,sans-serif"><span style="font-family:trebuchet ms,sans-serif">linux user number: 531218</span><br style="font-family:trebuchet ms,sans-serif">
<span style="font-family:trebuchet ms,sans-serif">==========================================================================</span><br></div><br>