This contribution analysis visualization uses a stacked bar chart to display the relative contribution of various microbial species (rows) across different samples (columns). The data is grouped by functional categories (COG identifiers), with each group rendered as a separate panel. The chart uses D3.v3 to render SVG, with color encoding for species and a legend labeled “Function.” Axes are labeled “Samples” and “Relative contribution,” and the chart is sized at 500x500 pixels. The layout supports multiple groups, each containing a series of stacked layers, enabling comparison of species contributions across samples within and between functional groups.