---
url: /mosaic/examples/splom.md
---
# Scatter Plot Matrix (SPLOM)

A scatter plot matrix enables inspection of pairwise bivariate distributions. Do points cluster or separate in some dimensions but not others? Select a region to highlight corresponding points across all plots.

## Specification

```py \[Python]
import vgplot as vg

penguins = vg.parquet("data/penguins.parquet")

brush = vg.selection.single()

view = vg.vconcat(
    vg.hconcat(
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_length", y="body_mass", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.y_axis("left"),
            vg.margin_left(45),
            vg.width(185),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_depth", y="body_mass", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="flipper_length", y="body_mass", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="body_mass", y="body_mass", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
    ),
    vg.hconcat(
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_length", y="flipper_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.y_axis("left"),
            vg.margin_left(45),
            vg.width(185),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_depth", y="flipper_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(
                penguins, x="flipper_length", y="flipper_length", fill="species", r=2
            ),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="body_mass", y="flipper_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
    ),
    vg.hconcat(
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_length", y="bill_depth", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.y_axis("left"),
            vg.margin_left(45),
            vg.width(185),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_depth", y="bill_depth", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="flipper_length", y="bill_depth", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="body_mass", y="bill_depth", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
        ),
    ),
    vg.hconcat(
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_length", y="bill_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.y_axis("left"),
            vg.x_axis("bottom"),
            vg.margin_left(45),
            vg.margin_bottom(35),
            vg.width(185),
            vg.height(175),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="bill_depth", y="bill_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.x_axis("bottom"),
            vg.height(175),
            vg.margin_bottom(35),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="flipper_length", y="bill_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.x_axis("bottom"),
            vg.height(175),
            vg.margin_bottom(35),
        ),
        vg.plot(
            vg.frame(stroke="#ccc"),
            vg.dot(penguins, x="body_mass", y="bill_length", fill="species", r=2),
            vg.interval_xy(bind=brush),
            vg.highlight(by=brush, opacity=0.1),
            vg.x_axis("bottom"),
            vg.height(175),
            vg.margin_bottom(35),
        ),
    ),
    plot_defaults={
        "xTicks": 3,
        "yTicks": 4,
        "xDomain": "Fixed",
        "yDomain": "Fixed",
        "colorDomain": "Fixed",
        "marginTop": 5,
        "marginBottom": 10,
        "marginLeft": 10,
        "marginRight": 5,
        "xAxis": None,
        "yAxis": None,
        "xLabelAnchor": "center",
        "yLabelAnchor": "center",
        "xTickFormat": "s",
        "yTickFormat": "s",
        "width": 150,
        "height": 150,
    },
)

```