VectorPaint share charts: verify percentages through four equal quadrants

English translation of the Chinese original, translated on 2026-10-27. Original publication dates, attribution, code and version notes are retained.

A share chart needs agreement between areas and numbers. Use fictional 50/25/25 data and a circular mask over four equal quadrants. This checked construction is not an automatic arbitrary-value pie-chart tool or a claim that estimated angles are precise.

Verify a shared denominator and total

Use mutually exclusive example counts of 50, 25 and 25 with one total of 100. Do not mix periods or denominators. Reserve legend space on an 800 by 800 pixel canvas and label the data fictional. Check raw counts and percentages before drawing; a complete circle does not prove complete source data.

Build four equal-area quadrants

Create four equal squares arranged as one larger square. Check joins and equal dimensions through available size controls or consistent copied/grid references. Give the two upper quadrants group A’s colour and the lower quadrants B and C. The equal construction establishes the intended proportions rather than eyeballed wedges.

Centre a circular mask on the quadrants

Place a true circle over the quadrant intersection with diameter matching the large square. Check symmetric edge contact before masking. An off-centre circle changes visible areas. The mask clips rectangles rather than converting them into independent sector paths. Retain the full construction as an editable reference.

Label names and percentages together

Place matching colour swatches, names and percentages below the chart. Label A as 50% and B/C as 25%, stating total 100 if raw counts are shown. External labels can be clearer than text squeezed into sectors. Keep legend order easy to relate to the chart and audit every colour/name/value match.

Avoid perspective that distorts area reading

Keep the chart front-facing rather than flattening it into a thick 3D ellipse, which can distort area perception. Emphasise a group through wording without enlarging its geometry. Hide labels to inspect the half-circle and two quarter-circle regions, then restore the legend and verify their meanings.

Check whether the construction fits new data

Changing A to 40 invalidates the half-circle construction; do not merely change labels. Use a suitable accurate alternative or a new geometry. This is not a universal template. A four-group 25% version remains compatible if colours and legend are updated. Keep each image paired with its actual dataset.

Inspect exported joins and labels

Save and inspect the outer circle, common centre, fills and legend after export. Distinguish renderer hairlines from real gaps through normal-size and background checks. Keep title, total and fictional-data context with the chart. Label filenames and explain the masked-rectangle structure for editable delivery.

Return to the construction for proportion errors

Inspect circle centring, quadrant boundaries and moved rectangles if proportions seem wrong. Recalculate from the source list rather than estimating areas. Check stacking and mask selection for missing colours. After correction, confirm agreement among counts, percentages, geometry and legend.