Scatter Plots

Scatter plots display the relationship between two (or three) metrics at a fixed step, without a traditional x-axis field. This is useful for exploring trade-offs like accuracy vs. compute or loss vs. accuracy.

2D scatter (scatter)

The mode string has no x-fields — two metrics act as the x and y axes:

malet-plot -exp_folder ./experiments/my_exp \
  -mode 'scatter--train_loss val_accuracy' \
  -filter 'step last'

Each point represents one hyperparameter configuration at the selected step.

3D scatter with color (scatter_heat)

Add a third metric for color encoding:

malet-plot -exp_folder ./experiments/my_exp \
  -mode 'scatter_heat--train_loss val_accuracy param_count' \
  -filter 'step last' \
  -colors viridis

The first two metrics are the x and y axes; the third metric determines point color. A colorbar is added automatically. Use -zscale log for logarithmic color scaling.

Multi-line support

• scatter supports up to 2 multi-line fields (color + marker)

• scatter_heat supports up to 1 multi-line field (marker only, since color is used for the third metric)

malet-plot -exp_folder ./experiments/my_exp \
  -mode 'scatter--train_loss val_accuracy' \
  -filter 'step last' \
  -multi_line_fields 'optimizer'

Python API

import matplotlib.pyplot as plt
from malet.experiment import ExperimentLog
from malet.plot_utils.plot_drawer import ax_draw_scatter

log = ExperimentLog.from_tsv('log.tsv')
df = log.melt_and_explode_metric(step=-1)

fig, ax = plt.subplots(figsize=(7, 6))
ax_draw_scatter(ax, df, y_fields=['train_loss', 'val_accuracy'],
                color='#d62728', markersize=15)
ax.set_xlabel('Train Loss')
ax.set_ylabel('Val Accuracy')
fig.savefig('scatter.png', dpi=150, bbox_inches='tight')

ax_draw_scatter parameters

Parameter	Type	Default	Description
ax	Axes	—	Matplotlib axes
df	DataFrame	—	Melted DataFrame with metric index level
y_fields	list	—	Exactly 2 metric names for x and y
color	str	'orange'	Marker face color
marker	str	'D'	Marker style
markersize	float	30	Base marker size (scaled 20x internally)

ax_draw_scatter_heat parameters

Same as ax_draw_scatter, but:

Parameter	Type	Default	Description
y_fields	list	—	Exactly 3 metric names (x, y, color)
cmap	str	'magma'	Colormap for the third metric
norm	Normalize	None	Color normalization