Spline area charts are spline charts with the whole area between the smooth curve line and the horizontal baseline filled with a palette color. Areas can be filled with plain, gradient or semi-transparent colors, pattern fills or external texture images.
Our US Sales demo charts show a smooth curve line joining the points at the intersection of each year value between 2000 and 2017 and the number of products sold in US in that year. The whole area between the line and the horizontal baseline is filled with the first palette color. The horizontal X baseline appears here as a category axis, with regular intervals for each year value. Area charts use also often a linear baseline, with X values distributed at random intervals.