# FAQ (Common Issues and the Fastest Troubleshooting Path)

This chapter helps you locate the cause with the shortest path when you encounter "nothing shows", "wrong rendering", or "weird interactions".

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## 0. Fast troubleshooting path (30-second version)

Check in order. This usually solves 80% of issues:

1. **Does coordinate system match SeriesType**
   - Cartesian2D: Line/Bar/Scatter/Heatmap
   - Polar2D: Radar

2. **Do you actually have data**
   - `series.Count > 0`
   - the serie has `seriesData.Count > 0`

3. **Do axis types match what your data means**
   - Category axis: `labels` is not empty; data `x/y` are indices (0/1/2...)
   - Value axis: `x/y` are continuous numeric values

4. **Any NaN / Infinity**

5. **Is data excluded by Value axis range**
   - Check if min/max are fixed
   - Check if `autoRangeMin/autoRangeMax` are disabled

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## 1. I clicked Preview but nothing shows

### Possible causes

- `seriesData` is empty
- `Serie.visible = false`
- coordinate system does not match SerieType (e.g. Radar in Cartesian2D)
- axis range does not include your data (common when Value axis range is locked manually)

### What to do

1. In the Inspector, find `series` and expand a Serie
2. Check:
   - whether `visible` is true
   - whether `seriesData` has any elements
3. Check the coordinate system:
   - Radar -> `coordinateSystem = Polar2D`
   - Line/Bar/Scatter/Heatmap -> `coordinateSystem = Cartesian2D`
4. If you are using Value axes:
   - first disable any "fixed min/max" range settings
   - enable both `autoRangeMin/autoRangeMax`, confirm it renders, then lock step-by-step

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## 2. Category axis has labels, but points/bars are not on labels

### Typical symptoms

- bars appear between two labels
- line points do not align to A/B/C

### Quick conclusion

- With a Category axis, `x` (or `y`) should usually be the **category index** (0/1/2/...), not an arbitrary value.

### What to do

- Check your data points:
  - `labels[0]` corresponds to `x=0`
  - `labels[1]` corresponds to `x=1`
- If you are making a bar chart:
  - set `LabelPlacement` to `CellCenter`

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## 3. Value axis range is weird (too large/too small)

### Possible causes

- Value axis range is locked (min/max)
- only one side is locked but the other side has extreme values
- rounding/unit snapped the range to an unsuitable unit

### What to do

1. First, revert to full auto range and confirm it renders
2. Then gradually add your constraints:
   - common for bar charts: `minValue=0` + `autoRangeMax=true`
3. If you see lots of weird decimal ticks:
   - set `labelFormat` first

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## 4. Line is broken / nothing renders

### Most common cause

- NaN / Infinity exists in your data

### What to do

- Filter at the data source:
  - `float.IsNaN(x/y/z)`
  - `float.IsInfinity(x/y/z)`

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## 5. Bar chart and labels do not align

### Quick conclusion

- 99% of the time, `LabelPlacement` is not the right one

### What to do

- Bar: prefer `LabelPlacement = CellCenter`
- Line/Scatter: prefer `LabelPlacement = Tick`

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## 6. Heatmap is all one color / looks flat

### Possible causes

- `autoRange=false` but `minValue/maxValue` are unreasonable
- `clamp=false` and extreme values stretch the color range
- all data points have the same `value` (or all are 0)

### What to do

1. Enable `autoRange`
2. Check whether data point `value` varies
3. If you need a fixed range:
   - set `minValue/maxValue` reasonably

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## 7. Radar labels are missing/messy

### Common cause

- dimension label sources are inconsistent

### Recommended approach

- For each Radar point:
  - `x = dimension index`
  - `value = numeric value`
  - `name = dimension name`

Also ensure Radar does not rely on Cartesian axis configuration to obtain labels.

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## 8. tooltip/hover/selection points to the wrong item or state is unstable

### Common cause

- new point identifiers are generated on every refresh

### What to do

- keep each point `SeriesData.id` stable
- avoid clearing and generating a completely new set of points with `Guid.NewGuid()` on every refresh

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## 9. I don't know which chapter to read

- If you are in the workflow stage (create/clone/preview/export): see `01_01-EditorWorkflow.md`
- If you are dealing with axes/range/alignment/unit/format: see section 7 of `00_02-WorkflowAndLibrary.md`
- If you need the data conventions for a specific chart (SeriesData.x/y/z): see section 8 of `00_02-WorkflowAndLibrary.md`
- If you just want copy-ready templates: see `04_08-CommonRecipes.md`