getNiceMaxY method

double getNiceMaxY(double maxY, { int targetIntervals = 5, })

Helper to calculate a "nice" maximum Y value for axis scaling.

Returns a value slightly larger than maxY that is a multiple of 1, 2, 5, or 10 times a power of 10, ensuring clean axis intervals.

Parameters:

• maxY - The maximum data value
• targetIntervals - Desired number of intervals (default 5)

Implementation

double getNiceMaxY(double maxY, {int targetIntervals = 5}) {
  if (maxY <= 0) return 1.0;

  final rawStep = maxY / targetIntervals;
  final magnitude = math.pow(10, (math.log(rawStep) / math.ln10).floor()).toDouble();
  final normalizedStep = rawStep / magnitude;

  double niceStep;
  if (normalizedStep <= 1.0) {
    niceStep = 1.0;
  } else if (normalizedStep <= 2.0) {
    niceStep = 2.0;
  } else if (normalizedStep <= 5.0) {
    niceStep = 5.0;
  } else {
    niceStep = 10.0;
  }

  final step = niceStep * magnitude;
  return step * targetIntervals;
}