2.6.3 Resolution recommendation

How the system decides the best time resolution

1. Measure the total time range

   • The system first calculates how much time you are looking at.

   • It converts the chosen start and end dates into milliseconds.

   • This gives a precise number that represents the full span of time.

2. Pick a base unit

• Based on the time span, the system chooses an initial time unit (seconds, minutes, hours, days, weeks, or months).
• This is done using simple rules:
  • Years → months
  • Months → weeks
  • Weeks → days
  • Days → hours
  • Hours → minutes
  • Minutes → seconds
• This ensures the starting unit makes sense for the total time range.

1. Determine how many points can fit on the chart

• The system assumes each data point needs at least 3 pixels to remain readable.
• For example, a 400-pixel-wide chart can display roughly 133 points (400 / 3).
• This is the maximum number of data points that can fit without making the chart look crowded.

1. Check different step sizes

• For the chosen unit, the system tests several step sizes (like 1 hour, 3 hours, 6 hours, etc.).
• For each step size, it calculates how many points the chart would need by dividing the total time in milliseconds by the step size in milliseconds.
• If the number of points is less than or equal to the maximum allowed, that step size is chosen.

1. Fallback if needed

• If none of the step sizes fit neatly, the system automatically moves to the next larger unit (e.g., hours → days) and uses a default step of 1.
• This ensures the chart is never too crowded, no matter the time range.

Example

• Time range: 2 days
• Chart width: 400 pixels → max 133 points
• Step options for hours: 1 hour, 3 hours, 6 hours, 12 hours
• The system calculates:
  • Total milliseconds / step in milliseconds = number of points
  • 2 days ÷ 1 hour → 48 points - fits
  • 2 days ÷ 3 hours → 16 points - also fits
• The first step size that fits (48 points) is selected.

Result: Time unit = hours, Step = 1

In short

It converts your chosen date range into milliseconds, calculates how many points can fit on the chart based on a simple 3-pixel-per-point rule, and then selects the most readable time unit and step size automatically.