CHARTS / PRACTICAL GUIDE
Line chart: examples and when to use it
A line chart connects observations in a meaningful order, usually time. It makes direction, turning points and differences between series easy to compare.
- Solar
- Wind
- Hydropower
When to use it
Use it for monthly revenue, daily prices or repeated measurements. Several lines work well when they share a unit and a common time axis.
When to choose another view
Use a bar chart for unordered categories. A line between separate products suggests a continuity that does not exist. Many overlapping series may be clearer as separate views.
How to read it
Read time from left to right and values against the vertical scale. Compare levels as well as slopes: a steep rise can reflect the axis range, not just a dramatic change in the data.
Data format and example
One date or ordered-period column and one or more numeric columns. Each row is an observation; each measure becomes a series.
| Year | Solar | Wind | Hydropower |
|---|---|---|---|
| 2000 | 1 | 31 | 267 |
| 2003 | 3 | 63 | 281 |
| 2006 | 8 | 133 | 309 |
| 2009 | 22 | 277 | 333 |
| 2012 | 100 | 526 | 369 |
| 2015 | 253 | 831 | 390 |
| 2018 | 584 | 1270 | 418 |
| 2021 | 1047 | 1848 | 443 |
| 2024 | 2130 | 2494 | 467 |
Make it in Datamon
- Paste the example or import your own spreadsheet. Confirm the date and decimal formats in Data.
- Choose Line in Visualize. Connect the period column to X and the measures to Y.
- Sort observations chronologically. Decide whether missing values should leave a gap or use an explicitly justified estimate.
- Add a unit, source and concise title. Adjust axis and label sizes in Refine, then export.
Common mistakes to check
- Do not turn blank cells into zero: a missing observation and a recorded zero mean different things.
- Interpolation is an estimate. Explain it and retain the original data; it cannot recover unknown observations.
- Avoid dense date labels. Show a readable selection of ticks while retaining the underlying observations.