Figure Space Monospace Equal Width Check

Audit figure-space glyph against each actual numeral advance, preserving digit-specific mismatch; not inferred from font being called monospace or its nominal em.

Description

Figure-space width can be checked against each measured numeral advance.

Figure-space width can be checked against each measured numeral advance. A monospace name alone does not establish equality.^[1]

Enter nonempty nonnegative digit advances, nonnegative space/tolerance. Return signed differences and inclusive all-digit flag.

When to use Figure Space Monospace Equal Width Check

Use Figure Space Monospace Equal Width Check when you need to evaluate the supplied records under the calculation and evidence rules below. No nominal em-width assumption or font-feature verification is added.

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.

How to use Figure Space Monospace Equal Width Check and understand its results

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.
Enter figureSpaceAdvanceUnits, numeralDigitAdvancesUnits, callerWidthToleranceUnits using the field table and calculation rules, then run the tool.
Read signedSpaceMinusDigitWidthsUnits, matchesAllMeasuredDigits. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
figureSpaceAdvanceUnits	Figure space advance units	number	Required
numeralDigitAdvancesUnits	Numeral digit advances units	list of number	Required
callerWidthToleranceUnits	Caller width tolerance units	number	Required

Enter nonempty nonnegative digit advances, nonnegative space/tolerance. Return signed differences and inclusive all-digit flag.

difference=figureSpaceAdvance−digitAdvance; allMatch when every abs difference≤tolerance

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
signedSpaceMinusDigitWidthsUnits	Signed space minus digit widths units	list of number
matchesAllMeasuredDigits	Matches all measured digits	boolean

json

{
  "input": {
    "figureSpaceAdvanceUnits": 500,
    "numeralDigitAdvancesUnits": [
      500,
      500,
      500
    ],
    "callerWidthToleranceUnits": 0
  },
  "output": {
    "signedSpaceMinusDigitWidthsUnits": [
      0,
      0,
      0
    ],
    "matchesAllMeasuredDigits": true
  }
}

Limitations and assumptions

No nominal em-width assumption or font-feature verification is added.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Proportional vs Tabular Numeral Width Check: Tabular figures use equal advances, while proportional figures may differ. A calibration sample should remain distinct from full-digit coverage. For a complementary task, use Ellipsis vs Three Periods Width Compare: An ellipsis and three periods can have different advances. Pair kerning contributes twice to the three-period sequence.

References

Figure Space Monospace Equal Width Check — tool.io

Similar or alternative tools

Proportional vs Tabular Numeral Width Check
Tabular figures use equal advances, while proportional figures may differ. A calibration sample should remain distinct from full-digit coverage.
Ellipsis vs Three Periods Width Compare
An ellipsis and three periods can have different advances. Pair kerning contributes twice to the three-period sequence.