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Mathematical Notation Parser - API Reference

Overview

The Mathematical Notation Parser provides a standardized system for mathematical notation in DSP algorithms. It supports validation, conversion between formats (LaTeX, Unicode, ASCII), and symbol lookup.

Installation

# No installation required - pure Python with PyYAML dependency
pip install pyyaml

Quick Start

from notation_parser import NotationParser

# Create parser instance
parser = NotationParser()

# Validate notation
result = parser.validate_notation("y[n] = x[n] + x[n-1]")
print(f"Valid: {result['valid']}")

# Convert to LaTeX
latex_eq = parser.to_latex("H(ω) = 1 / (1 + jω)")
print(latex_eq)  # H(\omega) = 1 / (1 + j\omega)

# Lookup symbol info
fc_info = parser.get_symbol_info("fc")
print(f"{fc_info.description}: {fc_info.range}")

Class: NotationParser

Main parser class for mathematical notation operations.

Constructor

NotationParser(schema_path: Optional[Path] = None)

Parameters: - schema_path (Optional[Path]): Path to notation schema YAML file. If None, uses default schema.

Example:

parser = NotationParser()  # Use default schema

# Or specify custom schema
from pathlib import Path
custom_parser = NotationParser(schema_path=Path("custom_notation.yaml"))


Methods

validate_notation(expression: str) -> Dict[str, Union[bool, List[str]]]

Validates that an expression uses standard notation.

Parameters: - expression (str): Mathematical expression to validate

Returns: - Dict with keys: - valid (bool): True if notation is valid - issues (List[str]): List of validation issues found

Example:

result = parser.validate_notation("y[n] = x(t) + z[n]")
print(result)
# {'valid': False, 'issues': ['Mixing discrete [n] and continuous (t) notation']}

Validation Rules: - Detects mixing of discrete [n] and continuous (t) notation - Checks for inconsistent parameter naming (e.g., fc vs f_c)


to_latex(expression: str) -> str

Converts expression from Unicode to LaTeX format.

Parameters: - expression (str): Mathematical expression with Unicode symbols

Returns: - str: LaTeX-formatted expression

Example:

unicode_eq = "H(ω) = ω0² / Q"
latex_eq = parser.to_latex(unicode_eq)
print(latex_eq)  # H(\omega) = \omega0² / Q

Conversions: - ω\omega - π\pi - \sum - \prod - \int - And more (see schema)


to_ascii(expression: str) -> str

Converts expression to ASCII-only format.

Parameters: - expression (str): Mathematical expression with Unicode symbols

Returns: - str: ASCII-only expression

Example:

unicode_eq = "y[n] = ω·x[n] + π"
ascii_eq = parser.to_ascii(unicode_eq)
print(ascii_eq)  # y[n] = w*x[n] + pi

Conversions: - ωw - πpi - ×* - ·* - And more


to_unicode(expression: str, from_format: str = 'ascii') -> str

Converts expression to Unicode format.

Parameters: - expression (str): Mathematical expression - from_format (str): Source format - 'ascii' or 'latex'

Returns: - str: Unicode-formatted expression

Example:

ascii_eq = "H(omega) = pi * f"
unicode_eq = parser.to_unicode(ascii_eq, from_format='ascii')
print(unicode_eq)  # H(ω) = π * f


get_symbol_info(symbol: str) -> Optional[MathSymbol]

Retrieves information about a mathematical symbol.

Parameters: - symbol (str): Symbol to lookup (e.g., "fc", "x[n]", "Q")

Returns: - MathSymbol object or None if not found

Example:

fc_info = parser.get_symbol_info("fc")
print(f"Symbol: {fc_info.symbol}")
print(f"Description: {fc_info.description}")
print(f"LaTeX: {fc_info.latex}")
print(f"Unit: {fc_info.unit}")
print(f"Range: {fc_info.range}")


list_symbols(category: Optional[str] = None, domain: Optional[str] = None) -> List[MathSymbol]

Lists all symbols, optionally filtered.

Parameters: - category (Optional[str]): Filter by category (not yet implemented) - domain (Optional[str]): Filter by domain - 'discrete', 'continuous', 'frequency'

Returns: - List of MathSymbol objects

Example:

# List all discrete time signals
discrete_symbols = parser.list_symbols(domain='discrete')
for sym in discrete_symbols:
    print(f"{sym.symbol}: {sym.description}")

# List all symbols
all_symbols = parser.list_symbols()
print(f"Total symbols: {len(all_symbols)}")


format_equation(equation: str, output_format: str = 'latex') -> str

Formats equation in specified output format.

Parameters: - equation (str): Mathematical equation - output_format (str): Desired format - 'latex', 'ascii', or 'unicode'

Returns: - str: Formatted equation

Example:

eq = "H(ω) = ω0 / Q"

latex = parser.format_equation(eq, output_format='latex')
ascii_eq = parser.format_equation(eq, output_format='ascii')
unicode_eq = parser.format_equation(eq, output_format='unicode')


generate_reference_doc(output_format: str = 'markdown') -> str

Generates reference documentation for notation system.

Parameters: - output_format (str): Format for output - currently only 'markdown' supported

Returns: - str: Formatted documentation

Example:

doc = parser.generate_reference_doc(output_format='markdown')
print(doc)

# Save to file
with open('notation_reference.md', 'w', encoding='utf-8') as f:
    f.write(doc)


Class: MathSymbol

Dataclass representing a mathematical symbol.

Attributes

@dataclass
class MathSymbol:
    symbol: str              # Symbol representation (e.g., "fc", "x[n]")
    description: str         # Human-readable description
    latex: str              # LaTeX representation
    domain: Optional[str]    # Domain: 'discrete', 'continuous', 'frequency'
    type: Optional[str]      # Type: 'signal', 'parameter', 'index', etc.
    unit: Optional[str]      # Physical unit (e.g., "Hz", "s")
    range: Optional[List[float]]  # Valid range [min, max]
    formula: Optional[str]   # Formula for derived parameters

Example

from notation_parser import MathSymbol

# Create custom symbol
cutoff_freq = MathSymbol(
    symbol='fc',
    description='Cutoff frequency',
    latex='f_c',
    domain='discrete',
    type='parameter',
    unit='Hz',
    range=[20, 20000]
)

print(f"{cutoff_freq.symbol}: {cutoff_freq.description}")
print(f"Valid range: {cutoff_freq.range[0]} to {cutoff_freq.range[1]} {cutoff_freq.unit}")

Schema Reference

The notation schema is defined in schemas/notation_schema.yaml.

Schema Structure

schema_version: "1.0.0"

signals:
  discrete_time: [...]      # Signals like x[n], y[n], h[n]
  continuous_time: [...]    # Signals like x(t), y(t)
  frequency_domain: [...]   # Signals like X(ω), H(jω)

parameters:
  filter: [...]             # Parameters like fc, Q, G
  envelope: [...]           # Parameters like A, D, S, R
  delay: [...]              # Parameters like D, fb, mix

operations:
  basic: [...]              # Operations like +, -, ×, /
  signal: [...]             # Operations like ∑, ∏, ∫
  functions: [...]          # Functions like sin(), exp(), log()

systems:
  difference_equation: {...}
  transfer_function_discrete: {...}
  transfer_function_continuous: {...}
  state_space: {...}

diagram_symbols: [...]      # Block diagram symbols

validation:
  naming_conventions: {...}
  consistency: [...]

export_formats:
  supported: [...]
  conversions: {...}

Adding Custom Symbols

To add custom symbols, modify notation_schema.yaml:

parameters:
  custom:
    - symbol: "my_param"
      description: "My custom parameter"
      type: "custom"
      latex: "\\text{my\\_param}"
      unit: "units"
      range: [0, 100]

Error Handling

The parser uses standard Python exceptions:

# ValueError for unsupported formats
try:
    parser.format_equation(eq, output_format='invalid')
except ValueError as e:
    print(f"Error: {e}")

# FileNotFoundError for missing schema
try:
    parser = NotationParser(schema_path=Path("missing.yaml"))
except FileNotFoundError as e:
    print(f"Schema not found: {e}")

Best Practices

1. Consistent Notation

Always use the same symbol for the same concept:

# GOOD
eq1 = "y[n] = fc·x[n]"
eq2 = "H(z) = 1 / (1 + fc·z⁻¹)"

# BAD - inconsistent
eq1 = "y[n] = fc·x[n]"
eq2 = "H(z) = 1 / (1 + f_c·z⁻¹)"  # Different notation for fc!

2. Validate Before Processing

# Always validate first
result = parser.validate_notation(equation)
if not result['valid']:
    print(f"Validation errors: {result['issues']}")
    # Handle errors...
else:
    # Process equation...
    latex = parser.to_latex(equation)

3. Use Appropriate Domains

Don't mix discrete and continuous notation:

# GOOD - discrete
discrete_eq = "y[n] = x[n] + x[n-1]"

# GOOD - continuous
continuous_eq = "y(t) = x(t) + dx/dt"

# BAD - mixed domains
mixed_eq = "y[n] = x(t) + z[n-1]"  # Will fail validation!

4. Document Units

Always specify units for physical parameters:

fc_info = parser.get_symbol_info("fc")
print(f"Cutoff frequency: {value} {fc_info.unit}")  # "Cutoff frequency: 1000 Hz"

Performance

  • Schema loading: ~10ms (cached after first load)
  • Validation: ~1ms per equation
  • Format conversion: ~0.5ms per equation
  • Symbol lookup: O(1) via dictionary

Version History

v1.0.0 (2025-10-10)

  • Initial release
  • Support for LaTeX, Unicode, ASCII formats
  • Comprehensive DSP symbol database
  • Validation system
  • Reference documentation generation

See Also