Function calculate_complementary_fragment_composition 

pub fn calculate_complementary_fragment_composition(
    precursor_composition: &HashMap<&str, i32>,
    fragment_composition: &HashMap<&str, i32>,
) -> HashMap<String, i32>

Calculate the atomic composition of the complementary fragment.

When a peptide is fragmented, the resulting fragment ion has a complementary portion (the rest of the precursor). This function calculates the atomic composition of that complementary fragment, which is needed for quad-selection dependent isotope distribution calculations.

Arguments

• precursor_composition - atomic composition of the full precursor
• fragment_composition - atomic composition of the fragment ion (from atomic_product_ion_composition)

Returns

• HashMap<String, i32> - atomic composition of the complementary fragment

Examples

use mscore::algorithm::peptide::{peptide_sequence_to_atomic_composition, atomic_product_ion_composition, calculate_complementary_fragment_composition};
use mscore::data::peptide::{PeptideSequence, PeptideProductIon, PeptideIon, FragmentType};

let precursor = PeptideSequence::new("PEPTIDE".to_string(), Some(1));
let precursor_comp = peptide_sequence_to_atomic_composition(&precursor);

// Create a b3 ion (PEP)
let b3_ion = PeptideProductIon {
    kind: FragmentType::B,
    ion: PeptideIon {
        sequence: PeptideSequence::new("PEP".to_string(), Some(1)),
        charge: 1,
        intensity: 1.0,
    },
};
let fragment_comp: Vec<(&str, i32)> = atomic_product_ion_composition(&b3_ion);
let fragment_map: std::collections::HashMap<&str, i32> = fragment_comp.into_iter().collect();

let complementary = calculate_complementary_fragment_composition(&precursor_comp, &fragment_map);
// Complementary should be TIDE as y-ion (precursor - b-ion)