Load and assign curves
Choose one LAS 1.2 or 2.0 file, drag it into the drop area, or use Try synthetic sample data. Limits: 25 MiB, 250,000 rows, 5,000,000 numeric values. The viewer starts with four empty tracks.
Find a curve in the LAS list. Drag it into a track, or select it and click the track’s + button. Any curve can appear in several tracks, once per track. Curve references preserve duplicate mnemonics as separate IDs. Remove a curve in Track setup. Changes are committed only by Apply changes.
Scales and line styles
Each curve has its own Min (left), Max (right), linear or log scale, colour, line style and thickness. Min greater than Max reverses the scale. Logarithmic endpoints must both be positive. Line styles: solid, dashed, dotted, dash–dot and long dash. Thickness: 0.5–10 px.
Initial limits are suggested from recognised mnemonics and units; check them before interpreting an overlay. No stored measurement values are converted. A density curve and a neutron curve use independent scales even when drawn in one track.
Fill to a baseline
In Track setup, enable Fill to a baseline for a curve. Enter the baseline in that curve’s LAS units. Choose the colours for Curve left of baseline and Curve right of baseline, plus opacity from 0–100%. For the worked example, GR uses 0→150 gAPI and a baseline of 75 gAPI.
Left/right is determined after the scale transform. Reversing a scale reverses the screen relationship. A baseline can be outside the view; only the visible part of the fill is drawn. On a log scale, its value must be positive.
Fill between two curves
One curve pair can be filled per track. Choose Curve A and Curve B from that track, enable the fill, then choose A left of B and A right of B colours. These names refer to screen position, not a numerical comparison between unlike units. Each curve keeps its own scale. Colours change at displayed crossings.
Missing values, non-positive log values and gaps in depth break the curves and the fills. The drawing is clipped to the track boundaries.
Depth and inspection
Set Top and Bottom and click Apply. Depth increases downwards. Fit all restores the full interval. Detail chooses a smaller window. Drag to pan; Ctrl/⌘ + scroll zooms at the pointer. The depth slider and Shallower/Deeper buttons also move the window. Hover or tap to read sample values.
With the plot focused, Arrow Up/Down and Page Up/Down pan; +/− zoom; Home fits the well; Esc clears the gesture/readout. The viewer sorts descending depth rows while retaining their original curve values. The report identifies reordered or duplicate depths.
Export and reuse
Export PNG includes all four tracks, visible depth interval, curve scales, styles and fill legends. It exports the current viewport; use Fit all first for the whole well. Save settings records all four tracks and the current depth window. Load settings requires the same source LAS. JSON imports support up to 256 curve entries per track.
Run the four-track example · Inspect the cemented interval · Settings reference