# Cycle not working with pgfplots \foreach

I'm trying to plot some data from a text file, and I would like to be able to cycle the styles of the markers using a custom list. I was able to get the cycle list working, but when I added error bars, problems arose. Originally, my code was as follows:

\documentclass[11pt]{standalone}

\usepackage{pgfplots}

\pgfplotsset{compat=1.8}

\pgfplotscreateplotcyclelist{mylist}{%
{black,mark=square,draw=none},
{black,mark=o,draw=none},
{black,mark=triangle,draw=none},
{black,mark=diamond,draw=none}}

\begin{document}
\begin{tikzpicture}
\begin{axis}[
legend pos=south east,
legend entries={Trial 1,
Trial 2,
Trial 3},
cycle list name=mylist,
legend image post style = only marks
]

\foreach \yindex in {2,4,6}
\addplot  table[x index = 0, y index = \yindex] {data.txt};
\end{axis}
\end{tikzpicture}
\end{document}


This produced the following image:

I then made the following change to be able to add the error columns to my plot, which resulted in a plot that didn't contain any of my marker information, but rather made straight lines between points with no markers.

\foreach[evaluate=\yindex as \ynext using int(\yindex+1)] \yindex in {2,4,6}
\addplot [error bars/.cd,y dir=both,y explicit, x dir = both, x explicit]
table[x index = 0, x error index = 1, y index = \yindex, y error index = \ynext]
{data.txt};


Any ideas that might have caused this problem and/or how to remedy it? I'd really appreciate it, thanks!

EDIT: Forgot to include the data file being loaded. If it is of interest, it is a simple tab delimited file. Alternating columns (1,3,5,7) correspond to plot values, and (2,4,6,8) correspond to the error bars associated. Columns 1 and 2 are the x axis.

23    0.25    1.75    0.0625    1.625    0.0625    1.75     0.0625
25    0.25    1.75    0.0625    1.75     0.0625    1.875    0.0625
27    0.25    2.125   0.0625    2        0.0625    2.25     0.0625
29    0.25    2.5     0.0625    2.5      0.0625    2.5      0.0625
31    0.25    2.5     0.0625    2.5      0.0625    2.5      0.0625
33    0.25    2.5     0.0625    2.5      0.0625    2.5      0.0625

-
Welcome to TeX.SX! –  Adam Liter Jan 29 '14 at 7:06
Also, a tip: you can use backticks  to mark inline code. So "\addplot" can be \addplot. –  Adam Liter Jan 29 '14 at 7:27

I was able to fix this by changing the \addplot command to \addplot+ and by adding the cycle list name parameter in the \addplot+ command. Hope this helps someone else!
\foreach[evaluate=\yindex as \ynext using int(\yindex+1)] \yindex in {2,4,6}
`