Files
CANveyor/stat/frequency.py
T

77 lines
3.0 KiB
Python

import argparse
import json
from pathlib import Path
import fastparquet
import pandas as pd
import plotly.express as px
import plotly.graph_objects as go
def _extract_identifier(row: pd.Series) -> str:
"""Extracts PGN from metadata or falls back to CAN ID."""
meta = row.get('j1939_metadata')
if pd.isna(meta):
return f"{row['ID']} "
if isinstance(meta, str):
try:
meta = json.loads(meta)
except json.JSONDecodeError:
return f"{row['ID']}"
if isinstance(meta, dict) and 'PGN' in meta:
return f"PGN: {meta['PGN']} "
return f"{row['ID']}"
def load_data(file_path: Path) -> pd.DataFrame:
"""Loads Parquet file and adds an Identifier column."""
df = pd.read_parquet(file_path)
df['Identifier'] = df.apply(_extract_identifier, axis=1)
return df
def calculate_frequency(df: pd.DataFrame) -> pd.DataFrame:
"""Calculates frequency counts and percentages for identifiers."""
freq_df = df['Identifier'].value_counts().reset_index()
freq_df.columns = ['Identifier', 'Count']
total_messages = freq_df['Count'].sum()
freq_df['Percentage'] = (freq_df['Count'] / total_messages * 100).round(2)
return freq_df.sort_values('Count', ascending=True)
def visualize_frequency(stats_df: pd.DataFrame, title: str = "CAN Bus Message Frequency") -> go.Figure:
"""Generates an interactive Plotly horizontal bar chart with a logarithmic x-axis."""
fig = px.bar(
stats_df, y='Identifier', x='Count', orientation='h', title=title, log_x=True,
labels={'Identifier': 'PGN / CAN ID', 'Count': 'Message Count'},
color='Count', color_continuous_scale='Turbo',
hover_data={'Percentage': ':.2f', 'Count': True, 'Identifier': True}
)
fig.update_layout(
height=max(600, len(stats_df) * 18), width=1000,
xaxis_title='Total Message Count (Log Scale)', yaxis_title='PGN or CAN ID',
yaxis={'categoryorder': 'total ascending'},
plot_bgcolor='rgba(0,0,0,0)', paper_bgcolor='white',
font=dict(family="Segoe UI, Arial, sans-serif", size=12),
hoverlabel=dict(bgcolor="white", font_size=13, font_family="Segoe UI"),
margin=dict(l=250, r=50, t=80, b=50),
title=dict(font=dict(size=20), x=0.5)
)
fig.update_traces(
hovertemplate="<b>%{y}</b><br>Count: %{x:,}<br>Share: %{customdata[0]}%<extra></extra>"
)
return fig
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Analyze CAN bus Parquet data.")
parser.add_argument("-i", "--input", type=Path, required=True)
parser.add_argument("-o", "--output", type=Path, default=Path("can_analysis_report.html"))
parser.add_argument("-t", "--title", type=str, default="CAN Bus Message Frequency by PGN / ID")
args = parser.parse_args()
df = load_data(args.input)
stats_df = calculate_frequency(df)
fig = visualize_frequency(stats_df, title=args.title)
fig.write_html(str(args.output), include_plotlyjs='cdn')