mermaid-js/mermaid · error · Error

Could not find a suitable point for the given distance

Error message

Could not find a suitable point for the given distance

What it means

Thrown by calculatePoint when it cannot interpolate a point at the requested distance along the polyline. The loop walks consecutive point pairs subtracting segment lengths; if it never reaches the remaining distance (e.g. points has fewer than 2 entries so prevPoint is never set, or distanceToTraverse exceeds total path length), control falls through to this throw. It's reached from traverseEdge, calcCardinalityPosition, and calcTerminalLabelPosition.

Source

Thrown at packages/mermaid/src/utils.ts:364

        // Calculate the coordinates
        const distanceRatio = remainingDistance / vectorDistance;
        if (distanceRatio <= 0) {
          return prevPoint;
        }
        if (distanceRatio >= 1) {
          return { x: point.x, y: point.y };
        }
        if (distanceRatio > 0 && distanceRatio < 1) {
          return {
            x: roundNumber((1 - distanceRatio) * prevPoint.x + distanceRatio * point.x, 5),
            y: roundNumber((1 - distanceRatio) * prevPoint.y + distanceRatio * point.y, 5),
          };
        }
      }
    }
    prevPoint = point;
  }
  throw new Error('Could not find a suitable point for the given distance');
};

const calcCardinalityPosition = (
  isRelationTypePresent: boolean,
  points: Point[],
  initialPosition: Point
) => {
  log.info(`our points ${JSON.stringify(points)}`);
  if (points[0] !== initialPosition) {
    points = points.reverse();
  }
  // Traverse only 25 total distance along points to find cardinality point
  const distanceToCardinalityPoint = 25;
  const center = calculatePoint(points, distanceToCardinalityPoint);
  // if relation is present (Arrows will be added), change cardinality point off-set distance (d)
  const d = isRelationTypePresent ? 10 : 5;
  //Calculate Angle for x and y axis
  const angle = Math.atan2(points[0].y - center.y, points[0].x - center.x);

View on GitHub (pinned to d93e9c88c0)

Solutions

1. Ensure edges have at least two distinct points before calculating label/cardinality positions.
2. Confirm layout has run and assigned real coordinates (not all-zero origin) before edge post-processing.
3. Guard callers: if (points.length < 2) return points[0] before calling calculatePoint.
4. For very short edges, clamp distanceToTraverse to a fraction of total length rather than a fixed 25.

Example fix

// before
calculatePoint([singlePoint], 25); // throws — no segment
// after
if (points.length < 2) return points[0];
return calculatePoint(points, Math.min(25, totalLength));

function safeCalculatePoint(points: { x: number; y: number }[], dist: number) {
  if (points.length < 2) return points[0];
  let total = 0;
  for (let i = 1; i < points.length; i++) total += Math.hypot(points[i].x - points[i-1].x, points[i].y - points[i-1].y);
  return calculatePoint(points, Math.min(dist, total));
}

function hasEnoughPoints(pts: unknown[]): pts is { x: number; y: number }[] { return pts.length >= 2; }

try { return calculatePoint(points, dist); } catch (e) { if (/suitable point/.test(String(e))) { return points[0]; } throw e; }

When it happens

Trigger: Calling calculatePoint with a single-point array (no segments → loop body never runs), with distanceToTraverse larger than the total polyline length, or with degenerate identical points whose total distance rounds to less than the target. The cardinality/terminal-label callers pass a fixed 25 (+markerSize) distance, so very short edges where total path < 25 can overshoot.

Common situations: A zero-length or self-loop edge whose points collapse to one coordinate, an edge between two identical node centers (overlapping nodes), or a diagram rendered before layout assigned positions (all points at origin). Also from custom edge routing that produces a single-point path.

Related errors

• The given radii are too small to create an arc between the p
• Edges array is required in layout data
• Could not calculate intersection points for rel "${rel.from}
• Line definition not found
• Unknown layout algorithm: ${data4Layout.layoutAlgorithm}

AI-assisted analysis of mermaid-js/mermaid@d93e9c88c0 (2026-08-12). Data as JSON: /api/errors/eae982ce23a4fbc8. Report an issue: GitHub.