kuva hist2d
Two-dimensional histogram (density grid) from two numeric columns.
Input: two numeric columns.
| Flag | Default | Description |
|---|---|---|
--x <COL> | 0 | X-axis column |
--y <COL> | 1 | Y-axis column |
--bins-x <N> | 10 | Number of bins on the X axis |
--bins-y <N> | 10 | Number of bins on the Y axis |
--colormap <NAME> | viridis | Color map: viridis, inferno, turbo, grayscale |
--correlation | off | Overlay Pearson correlation coefficient |
--log-count | off | Log-scale the color mapping via log₁₀(count+1). Useful when a dense core dominates the color scale and hides structure in surrounding low-density regions. Colorbar label updates to "log₁₀(Count + 1)" with tick marks at actual count values (1, 10, 100, …). |
--colorbar-tick-format <FMT> | auto | Colorbar tick label format: auto, sci, integer, fixed2. auto renders integers as-is and switches to scientific notation when counts reach 10 000. |
# Basic density grid
kuva hist2d measurements.tsv --x time --y value
# Fine-grained bins with correlation annotation
kuva hist2d measurements.tsv --x time --y value \
--bins-x 30 --bins-y 30 --colormap turbo --correlation
# Log color scale — reveals sparse structure around a dense core
kuva hist2d data.tsv --x x --y y --bins-x 30 --bins-y 30 --log-count
# Force scientific notation on the colorbar (e.g. for very large counts)
kuva hist2d data.tsv --x x --y y --colorbar-tick-format sci
See also: Shared flags — output, appearance, axes, log scale.