sweep

Unified LiDAR Parameter Sweep Tool

A comprehensive parameter sweep tool that combines the functionality of bg-sweep, bg-multisweep, and pcap-sweep into a single command with flexible sweep modes.

Build

go build -o app-sweep ./cmd/sweep
# or
make tools-local

Usage Modes

1. Multi-Parameter Sweep (Default)

Test all combinations of noise, closeness, and neighbor parameters:

./app-sweep \
  -mode=multi \
  -noise=0.005,0.01,0.02 \
  -closeness=1.5,2.0,2.5 \
  -neighbors=0,1,2 \
  -iterations=30

2. Single-Variable Sweeps

Noise Sweep (fix closeness and neighbor)

./app-sweep \
  -mode=noise \
  -noise-start=0.005 \
  -noise-end=0.03 \
  -noise-step=0.005 \
  -fixed-closeness=2.0 \
  -fixed-neighbor=1

Closeness Sweep (fix noise and neighbor)

./app-sweep \
  -mode=closeness \
  -closeness-start=1.5 \
  -closeness-end=3.0 \
  -closeness-step=0.5 \
  -fixed-noise=0.01 \
  -fixed-neighbor=1

Neighbor Sweep (fix noise and closeness)

./app-sweep \
  -mode=neighbor \
  -neighbor-start=0 \
  -neighbor-end=3 \
  -neighbor-step=1 \
  -fixed-noise=0.01 \
  -fixed-closeness=2.0

3. PCAP Mode

Run sweeps using PCAP file replay instead of live data:

./app-sweep \
  -mode=multi \
  -pcap=/path/to/lidar-data.pcap \
  -pcap-settle=20s \
  -noise=0.005,0.01,0.02 \
  -closeness=1.5,2.0,2.5 \
  -neighbors=0,1,2

Key Parameters

Common Options

• -monitor: Server URL (default: http://localhost:8081)
• -sensor: Sensor ID (default: hesai-pandar40p)
• -output: Output CSV filename (default: sweep-<mode>-<timestamp>.csv)
• -iterations: Number of samples per parameter combo (default: 30)
• -interval: Time between samples (default: 2s)

Sweep Mode

• -mode: One of multi, noise, closeness, neighbor

Parameter Specification

For Multi-Mode

• -noise: Comma-separated values (e.g., 0.005,0.01,0.02)
• -closeness: Comma-separated values (e.g., 1.5,2.0,2.5)
• -neighbors: Comma-separated values (e.g., 0,1,2)

For Single-Variable Modes

• Range parameters: -noise-start, -noise-end, -noise-step
• Range parameters: -closeness-start, -closeness-end, -closeness-step
• Range parameters: -neighbor-start, -neighbor-end, -neighbor-step
• Fixed parameters: -fixed-noise, -fixed-closeness, -fixed-neighbor

PCAP Options

• -pcap: Path to PCAP file (enables PCAP mode)
• -pcap-settle: Wait time after PCAP replay (default: 20s)

Other Options

• -seed: Seed behavior - true, false, or toggle (default: true)
• -settle-time: Wait for grid to settle in live mode (default: 5s)

Output Files

The tool generates two CSV files:

1. Summary file (sweep-<mode>-<timestamp>.csv):

   • One row per parameter combination
   • Mean and stddev for each acceptance bucket
   • Mean and stddev for nonzero cells
   • Mean and stddev for overall acceptance rate

2. Raw file (sweep-<mode>-<timestamp>-raw.csv):

   • One row per sample iteration
   • All raw acceptance counts, reject counts, totals, and rates per bucket
   • Nonzero cell count and overall acceptance for each sample
   • Timestamps for time-series analysis

Examples

Quick multi-parameter sweep (live data)

./app-sweep -mode=multi -noise=0.01,0.02 -closeness=2.0,2.5 -neighbors=1,2 -iterations=10

Detailed noise sweep with PCAP

./app-sweep \
  -mode=noise \
  -pcap=/Users/david/code/sensor_data/lidar/break-80k.pcapng \
  -noise-start=0.005 \
  -noise-end=0.02 \
  -noise-step=0.0025 \
  -fixed-closeness=2.5 \
  -fixed-neighbor=1 \
  -iterations=20 \
  -output=noise-sweep-detailed.csv

Full parameter space exploration

./app-sweep \
  -mode=multi \
  -noise=0.005,0.0075,0.01,0.015,0.02 \
  -closeness=1.5,2.0,2.5,3.0 \
  -neighbors=0,1,2,3 \
  -iterations=50 \
  -interval=3s

Migration from Old Tools

From bg-sweep

# Old:
./app-bg-sweep -start=0.01 -end=0.3 -step=0.01

# New:
./app-sweep -mode=noise -noise-start=0.01 -noise-end=0.3 -noise-step=0.01 \
  -fixed-closeness=2.0 -fixed-neighbor=1

From bg-multisweep

# Old:
./app-bg-multisweep -start=0.01 -end=0.02 -step=0.005 \
  -closeness=2.0,3.0 -neighbors=1,2

# New:
./app-sweep -mode=multi \
  -noise=0.01,0.015,0.02 -closeness=2.0,3.0 -neighbors=1,2

From pcap-sweep

# Old:
./app-pcap-sweep -pcap=/path/to/file.pcap -samples=5 -settle=5s

# New:
./app-sweep -mode=multi -pcap=/path/to/file.pcap \
  -iterations=5 -pcap-settle=5s \
  -noise=0.005,0.01,0.02 -closeness=1.5,2.0,2.5 -neighbors=0,1,2