# `Expresso.Element.Chart.Scatter.Data`
[🔗](https://github.com/rellen/expresso/blob/main/lib/expresso/element/chart/scatter/data.ex#L1)

The points of a scatter plot from the rows of a CSV file

The first row holds the headings, and each other row is one point. The
options `label`, `x`, `y`, `symbol`, `color` and `size` of the chart name
the column of each value, so a deck can show different columns of one
file:

| Option | The column | The default |
| --- | --- | --- |
| `label` | The name of the point | The first column |
| `x` | The x value, a number | `"x"` |
| `y` | The y value, a number | `"y"` |
| `symbol` | A category of the symbol | No symbol |
| `color` | A category of the color | No color |
| `size` | The size, a number more than zero | No size |
| `frames` | The label of the frame of the row | No frames |

An empty cell of the symbol or of the color gives the point no category. A
column of the color with a number in each cell that is not empty gives
each point a color from a number, on the scale of the `color_scale`
option.
With `frames`, each row is a point in one frame, and the function returns
each point with the label of its frame.

# `points`

```elixir
@spec points([{pos_integer(), [String.t()]}], String.t(), keyword()) ::
  {:ok, [Expresso.Element.Point.t() | {String.t(), Expresso.Element.Point.t()}]}
  | {:error, String.t()}
```

Return the points of the rows of a CSV file

`rows` are the rows of `Expresso.Element.Chart.Csv.rows/3`, with the
headings first. `columns` holds the options of the chart that name the
columns.

    iex> rows = [{1, ["service", "cost", "load"]}, {2, ["api", "1200", "840"]}]
    iex> {:ok, [point]} = Expresso.Element.Chart.Scatter.Data.points(rows, "a.csv", x: "cost", y: "load")
    iex> {point.name, point.x, point.y}
    {"api", 1200, 840}

---

*Consult [api-reference.md](api-reference.md) for complete listing*