Grid missing horizontal lines

Question

The following code:

\begin{figure}[!t]
\centering%
\begin{tikzpicture}[xscale=1,yscale=1,auto, inner sep=0pt,remember picture]
\node[anchor=north west,inner sep=0] (image) at (0,0) {\adjustbox{margin=1em,width=\textwidth,set height=4cm,set depth=4cm,frame,center}{Dummy}};
\begin{scope}[x={(image.north east)},y={(image.south west)}]
\draw[step=0.1,black,thin] (0,0) grid (1,1);
\foreach \x in {0,1,...,9} { \node [anchor=west] at (\x/10,0) {0.\x}; }
\foreach \y in {0,1,...,9} { \node [anchor=north] at (0,\y/10) {0.\y}; }
\end{scope}
\end{tikzpicture}
\end{figure}

generates:

   

Why are the horizontal lines missing?

I have the same problem with real figures (i.e. loading images with \includegraphics)

Answer 1

The grid function stumbles because the y vector is negative. If you draw the grid from the bottom up by specifying a ystep=-0.1, it works fine:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix}
\usepackage{adjustbox}

\begin{document}

\begin{tikzpicture}[xscale=1,yscale=1,auto, inner sep=0pt,remember picture]
\node[anchor=north west,inner sep=0] (image) at (0,0) {\adjustbox{margin=1em,width=\textwidth,set height=4cm,set depth=4cm,frame,center}{Dummy}};
\begin{scope}[x={(image.north east)},y={(image.south west)}]
\draw[xstep=0.1,ystep=-0.1,black,thin] (0,1) grid (1,0);
\foreach \x in {0,1,...,9} { \node [anchor=south] at (\x/10,0) {0.\x}; }
\foreach \y in {0,1,...,9} { \node [anchor=east] at (0,\y/10) {0.\y}; }
\end{scope}
\end{tikzpicture}



\end{document}