Data Chart Builder
Build publication-ready charts from CSV, JSON, FRED, or inline data.
Quick Start
python3 scripts/chart_builder.py --config chart.json
Workflow
1. Prepare data or identify source
Options:
- CSV file: Local or URL
- JSON: Inline in config or external file
- FRED: Federal Reserve series ID
- Inline: Direct data array in config
2. Write config JSON
{
"title": "My Chart Title",
"series": [
{
"csv": "/path/to/data.csv",
"date_col": "date",
"value_col": "price",
"label": "Stock Price",
"color": "#2E86AB",
"index": true
}
],
"output": "/tmp/my_chart.png"
}
3. Generate
python3 scripts/chart_builder.py --config my_chart.json
Config Reference
Top-level fields
| Field |
Type |
Description |
title |
string |
Chart title |
series |
array |
Data series to plot (required) |
output |
string |
Output path (default: /tmp/chart.png) |
figsize |
[w, h] |
Figure size in inches (default: [12, 7]) |
start_date / end_date |
string |
Filter range (YYYY-MM-DD) |
index_all |
bool |
Index all series to 100 |
fill |
bool |
Shade between first two series |
fill_color |
string |
Fill color (default: red) |
fill_alpha |
float |
Fill opacity (default: 0.15) |
hline |
number |
Draw horizontal reference line |
grid |
bool |
Show grid (default: true) |
ylim |
[min, max] |
Y-axis limits |
annotations |
array |
Vertical event markers |
Series fields
| Field |
Type |
Description |
label |
string |
Legend label (required) |
csv |
string |
Path or URL to CSV |
json |
string |
Path to JSON file |
fred |
string |
FRED series ID |
data |
array |
Inline data: [{"date": "...", "value": 100}, ...] |
date_col |
string |
Date column name (default: date) |
value_col |
string |
Value column name (default: value) |
type |
string |
line, bar, scatter |
color |
string |
Hex color |
width |
number |
Line width |
style |
string |
Line style: -, --, -., : |
index |
bool |
Index this series to 100 |
base_date |
string |
Index base date (default: first observation) |
Annotations
{
"date": "2008-09-15",
"label": "Lehman Bankruptcy",
"position": "top",
"y": 120,
"fontsize": 9
}
Examples
Economic comparison (FRED)
{
"title": "USA: GDP vs Wages (1959 = 100)",
"series": [
{"fred": "A939RX0Q048SBEA", "label": "GDP Per Capita", "color": "#2E86AB", "index": true},
{"fred": "COMPRNFB", "label": "Compensation Per Hour", "color": "#F18F01", "index": true}
],
"start_date": "1959-01-01",
"end_date": "1985-12-31",
"fill": true,
"annotations": [
{"date": "1971-08-15", "label": "Nixon Shock", "position": "top", "y": 140},
{"date": "1973-10-01", "label": "Oil Crisis", "position": "bottom", "y": 90}
],
"output": "gdp_wages.png"
}
Stock price vs volume
{
"title": "AAPL Price vs Volume",
"series": [
{"csv": "aapl.csv", "label": "Price", "color": "#2E86AB", "type": "line"},
{"csv": "aapl.csv", "label": "Volume", "color": "#F18F01", "type": "bar", "value_col": "volume"}
],
"output": "aapl_chart.png"
}
Inline data
{
"title": "Sales Q1-Q4",
"series": [
{
"label": "Revenue",
"data": [
{"date": "2024-01-01", "value": 100},
{"date": "2024-04-01", "value": 120},
{"date": "2024-07-01", "value": 140},
{"date": "2024-10-01", "value": 180}
],
"color": "#2E86AB",
"type": "bar"
}
],
"output": "sales.png"
}
Scatter plot
{
"title": "Height vs Weight",
"series": [
{"csv": "patients.csv", "label": "Male", "color": "blue", "type": "scatter", "date_col": "height", "value_col": "weight"},
{"csv": "patients.csv", "label": "Female", "color": "red", "type": "scatter", "date_col": "height", "value_col": "weight"}
]
}
Tips
- Indexing: Use
"index": true on each series or "index_all": true globally to compare growth rates on equal footing
- Colors: Use contrasting hex codes. Good pairs:
#2E86AB (blue) + #F18F01 (orange), or #C73E1D (red) + #3B1F2B (dark)
- Annotations: Alternate
position: "top" and "bottom" to avoid overlap
- Date parsing: Ensure dates are ISO format (YYYY-MM-DD) for reliable parsing
- FRED: Find series IDs at fred.stlouisfed.org
Data Source Flexibility
| Source |
How to specify |
Best for |
| Local CSV |
"csv": "/path/to/file.csv" |
Custom datasets |
| URL CSV |
"csv": "https://example.com/data.csv" |
API endpoints |
| FRED |
"fred": "GDPC1" |
Economic time series |
| Inline |
"data": [...] |
Small static datasets |