🗺️ plew-map

Continuous data on a calibrated image. Upload a CSV + background map, calibrate, and encode dimensions with color, size & shape. Click points for the full record with media.

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Data input

📁

Drop CSV + basemap PNGs (+ .calib.txt sidecars)
+ media, ELAN .eaf, Praat .TextGrid — or click

Location columnsStep 1

X column (e.g. loc::lon) Y column (e.g. loc::lat)

Web Mercator y-transform

Turn on when the background is a web-map screenshot (Google/OSM/Leaflet, EPSG:3857) and columns are lat/lon. Leave off for plain plots, equirectangular maps, or small extents (≲3° latitude). See design doc §4.

Background map

Try a basemap

Each PNG can ship with a .calib.txt sidecar (from make-basemap.py). Switch maps to compare layouts — calibration updates automatically.

CalibrationStep 2

Image edges Three-point Pixels

Type the data value at each image edge. Values are prefilled from the data range as an approximate starting point — for accurate placement, replace them with the image's true bounds (see the test-data README for the demo values).

Left edge (X)

Right edge (X)

Top edge (Y)

Bottom edge (Y)

Place 3 spread-out reference points on the image, then type each point's data coordinates. Handles rotation & skew.

CSV coordinates are already image pixels (origin top-left, y down). No parameters needed.

Edit positionsAfter calib

Drag points to move them

Click map to add a new point

Drag updates location columns live. Click map (with add mode on) places a new point and opens the annotation form. Click a point to view its record (audio/images). Shift+click to edit fields. Save to CSV keeps changes.

EncodingsStep 3

Color by

Continuous Categorical

Ramp

Low High

Size by

Continuous Categorical

Min px

Max px

Shape by (categorical only)

Filter categories

Uncheck values to hide them from the map. Click legend items too.

Explore speaker

Filter by person without using speaker as color or shape — useful when one speaker has several stimulus images (e.g. I01 + I02).

Only speakers with multiple stimuli

Show speakers

Display

Point size — scales all points: 9 px Opacity: 0.9

Outline points

Size as separate ring (open circle)

Fill shape keeps the base size & color; an independent open ring encodes the size variable — the two channels are visually de-linked.

Lat/lon graticule

Grid lines are drawn in data space through the calibration — so Mercator shows its unequal latitude spacing, and affine calibrations show tilt.

Spread stacked points

When several records share the same coordinates (e.g. municipality centroids), nudge them apart on the map. Visual only — saved CSV coordinates stay unchanged.

Map navigation: scroll to zoom · drag the map to pan · +/− on the map corner · drag the ⋮⋮ grip to move those controls · ⌂ resets view.

Export

Save to CSV downloads the dataset with the current calibration embedded as a reserved __PLEWMAP_CALIB__ row. Re-uploading that file auto-calibrates: location columns, the Mercator setting, and the edge values or three-point transform all restore automatically.

Legend

plew-map

🗺️

Upload a CSV and a background image to begin —
or press a Demo button in the sidebar to see plew-map reproduce an atlas-style language map and a TOEIC fluency scatter.

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🗺️ plew-map

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Record