resonance-strength-scaling

name	resonance-strength-scaling
description	Use this skill when scaling resonance strengths (ωγ) in ENSDF cL comment lines by a given factor and applying specified relative uncertainties. Handles dual-threshold uncertainty (e.g., 30% above cutoff, 50% below). Uses PDG sig-fig convention for ENSDF {In} formatting. Comment-only workflow — skip ruler and column validation.
argument-hint	["REFERENCE FACTOR UNCERTAINTY_PERCENT THRESHOLD_EV UNCERTAINTY_BELOW_PERCENT"]

Resonance Strength Scaling in ENSDF Comment Lines

ENSDF 80-column data record and field definitions, structural rules, column positions, and uncertainty notation: .github/agents/ENSDF-Agent.agent.md. Spot-check policy: .github/copilot-instructions.md.

Purpose

Scale |w|g (ωγ) resonance strength values from a specific NSR reference in cL comment lines by a constant factor, then assign relative uncertainties using the ENSDF {In} notation.

When to Use

• A reference's resonance strengths need renormalization (e.g., updated standard)
• Relative uncertainties must be assigned or revised
• Bulk scaling of comment-line values from one NSR reference

Prerequisites

• Target file: *.ens ENSDF file with cL comment lines containing |w|g values from a specific NSR reference
• Recognized value formats (all occur in practice):
  • |w|g=X.X eV {In} (NSR_REF). — standard format with uncertainty
  • |w|g=X.X eV (NSR_REF). — standard format without uncertainty
  • |w|g=(X.XX) eV (NSR_REF). — value in parentheses (tentative/uncertain), with =
  • |w|g(X.XX) eV (NSR_REF). — value in parentheses, missing = (typo in original data; can flag for correction)
• Know: scaling factor and direction (multiply or divide the old value)
• Know: uncertainty rule — one of: assign new % (uniform or dual-threshold), preserve existing {In}, or add no uncertainty
• Know: which levels are in scope (e.g., above a certain energy, below the d-line)

Workflow

Step 1: Identify Targets

# Find all target lines: cL comments with |w|g and the specific NSR reference
# Only below the d-line and above the minimum level energy
with open('file.ens', 'r') as f:
    lines = f.readlines()

for i, line in enumerate(lines):
    if 'NSR_REF' in line and '|w|g' in line and i >= d_line_index:
        # This is a target

Step 2: Extract Parent Level Energy

For each target cL line, walk backwards to find the parent L-record:

for j in range(i-1, -1, -1):
    if lines[j][5:8] == '  L':
        level_energy = lines[j][9:19].strip()
        break

Step 3: Compute Scaled Value and Uncertainty

import math

factor = 2.21052631579   # example: divide by factor (> 1 means scaling value DOWN)
# For scale-up: multiply instead: scaled = old_value * factor
scaled = old_value / factor   # divide case (most common for renormalization corrections)

# Uncertainty handling — choose one based on task specification:
# (a) Assign new relative uncertainty (no existing {In} or replacing it)
rel_unc = 0.30            # e.g., 30% uniform
unc = scaled * rel_unc
# (b) Preserve existing relative uncertainty (near-unity factor or paper-quoted unc)
rel_unc = old_unc / old_value  # back-compute from existing {In}
unc = scaled * rel_unc
# (c) No uncertainty added — leave {In} absent

Step 4: Apply PDG Significant Figure Convention

Per .github/agents/ENSDF-Agent.agent.md § ENSDF Uncertainty Notation Rules:

• Leading digit of uncertainty 1, 2, or <35 → 2 significant figures
• Leading digit ≥35, or 4-9 → 1 significant figure

mag = math.floor(math.log10(unc))
# Get leading digits
leading = int(round(unc / (10 ** (mag - 1))))
sig_figs = 2 if leading < 35 else 1
round_to = mag - 1 if sig_figs == 2 else mag

rounded_val = round(scaled, -round_to)
rounded_unc = round(unc, -round_to)

if round_to >= 0:
    val_str = '{:.0f}'.format(rounded_val)
    unc_int = int(round(rounded_unc))
else:
    decimals = -round_to
    val_str = '{:.{}f}'.format(rounded_val, decimals)
    unc_int = int(round(rounded_unc * 10**decimals))

Step 5: Format ENSDF Comment Line

 35CL cL $|w|g=<val_str> eV {I<unc_int>} (NSR_REF).

• Pad to exactly 80 characters with trailing spaces
• Preserve any suffix text (e.g., , possible doublet.)

Step 6: Apply Edits

Use replace_string_in_file or multi_replace_string_in_file with 3-line context blocks (prev + target + next) to ensure unique matching.

Step 7: Validate

Since this is a comment-only task, skip ruler/column validation per ENSDF-Agent.agent.md.

Run verification:

• Count all target lines matches expected total
• All lines are exactly 80 characters
• All targets are below d-line
• Bidirectional positional check (first and last entries)
• Random 5% spot check with forward computation from original values

Special Cases

No Original Uncertainty, New % Assigned

If the original value has no {In} (e.g., |w|g=4.8 eV (1976Me12)) and the task specifies a relative uncertainty, compute and apply it to the scaled value normally.

No Uncertainty Added

Some references (e.g., 1973Fa07 in the A=35 dataset) have |w|g values scaled with no uncertainty assigned in the output. In this case, write only the scaled value with no {In} tag: |w|g=X.XX eV (NSR_REF).

Dual-Threshold Uncertainty

Some references state different relative uncertainties for weak vs strong resonances:

• Example: 30% for ≥1 eV original (≥0.452 eV scaled), 50% for <1 eV original (<0.452 eV scaled)
• The threshold applies to the pre-scaling value or equivalently to the post-scaling value divided back

Suffix Text Preservation

Lines with extra text after the NSR reference (e.g., , possible doublet.) must preserve that text exactly.

Near-Unity Factor / Preserve Existing {In}

When the scaling factor is very close to 1 (e.g., 9.9/9.5 = 1.042), values change only slightly. If the existing {In} values are quoted directly from the paper's measurement uncertainties (not from a normalization convention), preserve the original {In} and update only the numeric value. Round the scaled value to the same number of decimal places as the original. Lines where the value rounds back to the original (no visible change) require NO edit.

Parenthetical Value Format

Lines with |w|g=(X.XX) eV (parentheses around value, with =) appear alongside standard lines. Scale the numeric value inside the parentheses and preserve the parenthetical format. Lines with |w|g(X.XX) eV (missing =) are likely typos; scale them and flag for a separate formatting correction.

Skip Specific Resonances

User may exclude specific resonances (e.g., "1213 resonance already cleaned"). Verify by checking the parent level's resonance energy in the S-field or via the level energy.

PDG Convention Quick Reference

Uncertainty Leading Digits	Sig Figs	Example
10-34	2	0.0286 → {I29}, 0.132 → {I13}
35-99	1	0.042 → {I4}, 0.38 → {I4}
Borderline 29.86→30	2→1 after rounding	Check after rounding

Common Pitfalls

1. False positives in verification: New scaled values may coincidentally match old value patterns from other entries (e.g., old 2.8→new 1.3, which looks like old 1.3)
2. Line count changes: Monitor file line count before/after edits to detect accidental line deletions
3. Duplicate content lines: Many targets have identical content; use 3-line context blocks for unique matching
4. Reverse-computation round trips: Verifying by back-computing may fail at rounding boundaries; always verify forward from original values