Merge pull request 'Implement entropy heatmap for CAN frames' (#2) from dev-entropy-heatmap into main

Reviewed-on: erickahmed/CANveyor#2
This commit was merged in pull request #2.
This commit is contained in:
2026-07-13 21:17:33 +02:00
7 changed files with 335 additions and 50 deletions
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# File: decoder.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
import argparse
import polars as pl
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# File: main.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
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# File: parser.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
import re
import csv
import polars as pl
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# File: entropy.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
import argparse
from pathlib import Path
import numpy as np
import pandas as pd
import plotly.graph_objects as go
from utils.extractor import load_data
def _to_int(x):
"""Convert a hex string or integer to int, returning NaN on failure."""
if isinstance(x, (int, np.integer)):
return int(x)
if isinstance(x, str):
try:
return int(x, 16)
except ValueError:
return np.nan
return np.nan
def calculate_byte_entropy(df: pd.DataFrame) -> pd.DataFrame:
"""Calculates Shannon entropy per byte position for each identifier."""
byte_cols = [f"b{i}" for i in range(8)]
available_cols = [col for col in byte_cols if col in df.columns]
if not available_cols:
raise ValueError("No byte columns (b0-b7) found in the DataFrame")
df_bytes = df[available_cols].copy()
for col in available_cols:
df_bytes[col] = df_bytes[col].apply(_to_int)
def entropy(s: pd.Series) -> float:
s = s.dropna()
if s.empty:
return 0.0
p = s.value_counts(normalize=True)
return -np.sum(p * np.log2(p))
return df.groupby("Identifier")[available_cols].agg(entropy)
def plot_entropy_heatmap(entropy_df: pd.DataFrame, title: str) -> go.Figure:
"""Generates an interactive heatmap of byte-level Shannon entropy."""
x = entropy_df.columns.tolist()
y = entropy_df.index.tolist()
z = entropy_df.values
fig = go.Figure(
data=go.Heatmap(
z=z,
x=x,
y=y,
colorscale=[
[0.0, "#ffffff"],
[0.15, "#fff7ec"],
[0.35, "#fee8c8"],
[0.55, "#fdd49e"],
[0.75, "#fdbb84"],
[1.0, "#ef6548"],
],
xgap=3,
ygap=3,
text=np.round(z, 2),
texttemplate="%{text}",
textfont={
"size": 11,
"color": "#2a2a2a",
"family": "Segoe UI, Arial, sans-serif",
},
hoverongaps=False,
hovertemplate=(
"<b>%{y}</b><br>"
"Byte %{x}: %{z:.2f} bits<extra></extra>"
),
colorbar=dict(
title=dict(
text="Entropy (bits)",
side="top",
font=dict(size=13, color="#1a1a1a"),
),
orientation="h",
thickness=15,
len=0.35,
x=1.0,
xanchor="right",
y=1.02,
yanchor="bottom",
tickfont=dict(size=11, color="#2a2a2a"),
tickformat=".1f",
outlinewidth=0.5,
outlinecolor="#cccccc",
),
)
)
fig.update_layout(
title=dict(
text=title,
font=dict(size=20, color="#1a1a1a"),
x=0.5,
xanchor="center",
pad=dict(b=20),
),
height=max(600, len(y) * 28 + 150),
autosize=True,
template="plotly_white",
xaxis=dict(
title=dict(text="Byte Position", font=dict(size=13, color="#1a1a1a")),
side="top",
dtick=1,
showgrid=False,
linecolor="#bdbdbd",
tickfont=dict(size=12, color="#2a2a2a"),
ticks="outside",
ticklen=4,
tickcolor="#cccccc",
),
yaxis=dict(
title=dict(text="PGN or CAN ID", font=dict(size=13, color="#1a1a1a")),
autorange="reversed",
showgrid=False,
linecolor="#bdbdbd",
tickfont=dict(size=12, color="#2a2a2a"),
ticks="outside",
ticklen=4,
tickcolor="#cccccc",
automargin=True,
),
font=dict(family="Segoe UI, Arial, sans-serif", size=12, color="#2a2a2a"),
hoverlabel=dict(
bgcolor="white",
font_size=13,
font_family="Segoe UI",
bordercolor="#cccccc",
),
margin=dict(l=200, r=40, t=120, b=60),
)
return fig
if __name__ == "__main__":
parser = argparse.ArgumentParser(
description="Analyze CAN bus byte-level entropy"
)
parser.add_argument(
"input", type=Path, help="Path to the input CAN log file"
)
parser.add_argument(
"output",
type=Path,
nargs="?",
default=Path("entropy_report.html"),
help="Path to the output HTML report",
)
parser.add_argument(
"title",
nargs="?",
default="CAN Bus Byte-Level Entropy",
help="Title for the HTML report",
)
args = parser.parse_args()
df = load_data(args.input)
entropy_df = calculate_byte_entropy(df)
fig = plot_entropy_heatmap(entropy_df, title=args.title)
config = {
"responsive": True,
"displaylogo": False,
"scrollZoom": True,
"modeBarButtonsToAdd": ["toggleSpikelines"],
"toImageButtonOptions": {"format": "png", "scale": 2},
}
fig.write_html(str(args.output), include_plotlyjs="cdn", config=config)
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# File: frequency.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
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
from utils.extractor import load_data
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:
def calc_freq(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)
total = freq_df['Count'].sum()
freq_df['Percentage'] = (freq_df['Count'] / total * 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."""
def plot_freq(stats_df: pd.DataFrame, title: str) -> go.Figure:
"""Generates interactive horizontal bar chart with log 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}
range_color=(stats_df['Count'].min(), stats_df['Count'].max()),
hover_data={'Percentage': ':.2f', 'Count': ':,', '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)
height=max(600, len(stats_df) * 18),
autosize=True,
template='plotly_white',
xaxis=dict(
title=dict(text="Message count [log scale]", font=dict(size=13, color="#1a1a1a")),
side="top",
dtick=1,
showgrid=False,
linecolor="#bdbdbd",
tickfont=dict(size=12, color="#2a2a2a"),
ticks="outside",
ticklen=4,
tickcolor="#cccccc",
),
yaxis=dict(
title=dict(text="PGN or CAN ID", font=dict(size=13, color="#1a1a1a")),
#autorange="",
showgrid=False,
linecolor="#bdbdbd",
tickfont=dict(size=12, color="#2a2a2a"),
ticks="outside",
ticklen=4,
tickcolor="#cccccc",
automargin=True,
),
font=dict(family="Segoe UI, Arial, sans-serif", size=12, color='#2a2a2a'),
hoverlabel=dict(bgcolor="white", font_size=13, font_family="Segoe UI",
bordercolor='#cccccc'),
margin=dict(l=200, r=40, t=120, b=60),
bargap=0.35,
coloraxis_colorbar=dict(
title=dict(text='Message Count', side='top'),
orientation='h',
thickness=15,
len=0.35,
x=1.0,
xanchor='right',
y=1.02,
yanchor='bottom',
tickformat=',',
outlinecolor='#cccccc',
outlinewidth=0.5
),
title=dict(font=dict(size=20, color='#1a1a1a'), x=0.5, xanchor='center',
pad=dict(b=20))
)
fig.update_xaxes(
showgrid=True, gridwidth=0.5, gridcolor='#e8e8e8',
zeroline=False, linecolor='#bdbdbd', mirror=False,
tickformat=',',
minor=dict(showgrid=True, gridcolor='#f4f4f4', gridwidth=0.5)
)
fig.update_yaxes(
showgrid=False, zeroline=False, linecolor='#bdbdbd',
ticks='outside', ticklen=4, tickcolor='#cccccc',
automargin=True
)
fig.update_traces(
hovertemplate="<b>%{y}</b><br>Count: %{x:,}<br>Share: %{customdata[0]}%<extra></extra>"
hovertemplate="<b>%{y}</b><br>Count: %{x:,}<br>Share: %{customdata[0]}%<extra></extra>",
marker_line_width=0,
texttemplate='%{x:,}',
textposition='outside',
textfont=dict(size=10, color='#666666'),
cliponaxis=False,
selected=dict(marker=dict(opacity=0.6)),
unselected=dict(marker=dict(opacity=0.2))
)
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")
parser = argparse.ArgumentParser(description="Analyze CAN bus message frequency")
parser.add_argument("input", type=Path, help="Path to the input CAN log file")
parser.add_argument("output", type=Path, nargs="?", default=Path("freq_report.html"), help="Path to the output HTML report")
parser.add_argument("title", nargs="?", default="CAN Bus Message Frequency", help="Title for the HTML report")
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')
stats = calc_freq(df)
fig = plot_freq(stats, title=args.title)
config = {
'responsive': True,
'displaylogo': False,
'scrollZoom': True,
'modeBarButtonsToAdd': ['toggleSpikelines'],
'toImageButtonOptions': {'format': 'png', 'scale': 2}
}
fig.write_html(str(args.output), include_plotlyjs='cdn', config=config)
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# File: extractor.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
import json
from pathlib import Path
import pandas as pd
def extract_id(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"ID: {row['ID']}"
if isinstance(meta, str):
try:
meta = json.loads(meta)
except json.JSONDecodeError:
return f"ID: {row['ID']}"
if isinstance(meta, dict) and 'PGN' in meta:
return f"PGN: {meta['PGN']}"
return f"ID: {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_id, axis=1)
return df
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# File: extractor.py
# Copyright (C) 2026 Erick Ahmed
# SPDX-License-Identifier: AGPL-3.0-or-later
import json
from pathlib import Path
import pandas as pd
def extract_id(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"ID: {row['ID']}"
if isinstance(meta, str):
try:
meta = json.loads(meta)
except json.JSONDecodeError:
return f"ID: {row['ID']}"
if isinstance(meta, dict) and 'PGN' in meta:
return f"PGN: {meta['PGN']}"
return f"ID: {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_id, axis=1)
return df