\begin{tikzpicture}
\pgfplotstableread[col sep=comma]{./data/featuremat_toydata_ard_full.csv}{\datatableC};
\begin{axis}[
    view={0}{90},
    title={ARD-full},
    ylabel={Toy data},
    % title style={font=\small},
    % ylabel style={font=\scriptsize},
    width=0.25\columnwidth,
    height=0.25\columnwidth,
    xmin=-0.5, xmax=19.5,
    ymin=-0.5, ymax=19.5,
    xtick=\empty,xlabel=\empty,
    ytick=\empty,%ylabel=\empty,
    % colorbar,
    colorbar style={width=2mm,
                    ytick={0,0.25,0.5,0.75,1.0},
                    yticklabels={{0},{0.25},{0.5},{0.75},{1.0}},
                    ticklabel style={font=\scriptsize},
                    at={(1.2,0.5)},anchor=east,
                    },
    colormap/viridis,
    point meta min=0, % Adjust the minimum value for the color mapping
    point meta max=1.0,  % Adjust the maximum value for the color mapping
    mesh/cols=20,
    ]
\addplot3[matrix plot] table[col sep=comma] {\datatableC};
\end{axis}
\end{tikzpicture}