Source code for matchms.filtering.peak_processing.require_minimum_number_of_peaks

import logging
from math import ceil
from typing import Optional
from matchms.typing import SpectrumType


logger = logging.getLogger("matchms")


def require_minimum_number_of_peaks(spectrum_in: SpectrumType,
                                    n_required: int = 10,
                                    ratio_required: Optional[float] = None) -> SpectrumType:
    """Spectrum will be set to None when it has fewer peaks than required.

    Parameters
    ----------
    spectrum_in:
        Input spectrum.
    n_required:
        Number of minimum required peaks. Spectra with fewer peaks will be set
        to 'None'.
    ratio_required:
        Set desired ratio between minimum number of peaks and parent mass.
        Default is None.

    """
    if spectrum_in is None:
        return None

    spectrum = spectrum_in.clone()

    parent_mass = spectrum.get("parent_mass", None)
    if parent_mass and ratio_required:
        n_required_by_mass = int(ceil(ratio_required * parent_mass))
        threshold = max(n_required, n_required_by_mass)
    else:
        threshold = n_required

    if spectrum.peaks.intensities.size < threshold:
        logger.info("Spectrum with %s (<%s) peaks was set to None.",
                    str(spectrum.peaks.intensities.size), str(threshold))
        return None

    return spectrum