Genomic Left Closed Right Open Length Term Tool

Description

Return length and last included position of a half-open interval.

Genome annotations depend on coordinate origin, endpoint inclusion, strand and reading-phase conventions. A local offset or phase token can be handled precisely while a complete transcript, reference identity and biological reading frame remain separate validation questions.

Return length and last included position of a half-open interval.

When to use this tool

Use Genomic Left Closed Right Open Length Term when checking the stated genomic coordinate, annotation phase or attribute-value convention.

How to use the tool and how it works

Enter start, end. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read length, lastIncluded, empty. Inspect empty before interpreting the associated values.

Return length and last included position of a half-open interval. Require whole 0 <= start <= end; length = end-start, empty tests equality, lastIncluded = end-1 or -1 when empty.^[1]

BED uses a zero-based start and an excluded end; block starts are relative to the enclosing chromosome start. The complete record has additional constraints.^[2]

Input field	Meaning and units	Accepted input
start	Start	Required. Safe integer; minimum 0.
end	End	Required. Safe integer.

Output field	Interpretation	Returned shape
length	Length	Required. Safe integer.
lastIncluded	end-1, or -1 sentinel for an empty half-open interval.	Required. Safe integer.
empty	Empty	Required. Boolean.

json

{
  "input": {
    "start": 100,
    "end": 150
  },
  "output": {
    "length": 50,
    "lastIncluded": 149,
    "empty": false
  }
}

Limitations and assumptions

No chromosome bounds or reference identity are checked; the empty last-position sentinel is not a real genomic coordinate.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use the intended complete BED/GFF/GTF format, reference assembly and transcript model to validate full annotations and biological meaning.

References

Calculation and input contract: bioinformatics/genomic-left-closed-right-open-length-term — tool.io
Genome Browser data file formats: BED — UCSC Genome Browser

Similar or alternative tools

Phasing Block Span
Return a phasing-block span under an endpoint convention.
Reverse Strand One Coordinate Transform
Reverse one zero-based sequence coordinate.