# Placement of rectangles next to each other

I want to have some rectangle nodes horizontally adjacent to each other.

My attempt at this is ok, but unfortunately it places the outer part of the edges adjacent to each other, so the border between rectangles looks twice as thick.

I would like the midpoint of the edges to be adjacent to each other. Is there a way to do this?

Here is my sample code:

\documentclass[border=6mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}[
box/.style={minimum height=0.5cm, draw=black, inner sep=0, thick}
]

\foreach \k in {0,...,7}
{
\coordinate (a) at (\k*3cm,0);
\pgfmathsetmacro\wa{1.8cm+0.4cm*cos(\k*60)}
\pgfmathsetmacro\wb{0.2cm+0.05cm*cos(\k*47)}
\node[fill=red!50!white, minimum width=\wa, box, anchor=west] (boxa) at (a) {};
\node[fill={rgb:green,1;white,1;black,1}, minimum width=\wb, box, anchor=west] (boxb) at (boxa.east) {};
}

\end{tikzpicture}
\end{document}


Sorry, misread the question. Just shift back by -\pgflinewidth.

\documentclass[border=6mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}[
box/.style={minimum height=0.5cm, draw=black, inner sep=0, thick}
]

\foreach \k in {0,...,7}
{
\coordinate (a) at (\k*3cm,0);
\pgfmathsetmacro\wa{1.8cm+0.4cm*cos(\k*60)}
\pgfmathsetmacro\wb{0.2cm+0.05cm*cos(\k*47)}
\node[fill=red!50!white, minimum width=\wa, box, anchor=west] (boxa) at (a) {};
\node[fill={rgb:green,1;white,1;black,1}, minimum width=\wb, box,
anchor=west] (boxb) at ([xshift=-\pgflinewidth]boxa.east) {};
}

\end{tikzpicture}
\end{document}