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Utils

These functions are used within the various experiment classes and it's unlikely you'll need them while performing data analysis using magnetopy. Future development of new classes for new experiments may find these useful, though.

add_uncorrected_moment_columns(experiment)

DataFrames from .dat files containing dc data have different columns for the moment depending on whether the measurement was done in VSM or DC mode. This function adds a column called "uncorrected_moment" and "uncorrected_moment_err" that contains the moment and moment error from the .dat file, regardless of whether the measurement was done in VSM or DC mode.

Parameters:

Name Type Description Default
experiment DcExperiment

A DcExperiment object (likely either a MvsH, ZFC, or FC object).

 required
Source code in magnetopy\experiments\utils.py 
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def add_uncorrected_moment_columns(experiment: DcExperiment) -> None:
    """`DataFrame`s from .dat files containing dc data have different columns for the
    moment depending on whether the measurement was done in VSM or DC mode. This
    function adds a column called "uncorrected_moment" and "uncorrected_moment_err"
    that contains the moment and moment error from the .dat file, regardless of
    whether the measurement was done in VSM or DC mode.

    Parameters
    ----------
    experiment : DcExperiment
        A `DcExperiment` object (likely either a `MvsH`, `ZFC`, or `FC` object).
    """
    # set "uncorrected_moment" to be the moment directly from the dat file
    # whether the measurement was dc or vsm
    experiment.data["uncorrected_moment"] = experiment.data["Moment (emu)"].fillna(
        experiment.data["DC Moment Free Ctr (emu)"]
    )
    experiment.data["uncorrected_moment_err"] = experiment.data[
        "M. Std. Err. (emu)"
    ].fillna(experiment.data["DC Moment Err Free Ctr (emu)"])

scale_dc_data(experiment, mass=0, eicosane_mass=0, molecular_weight=0, diamagnetic_correction=0)

Adds columns to the data attribute of a DcExperiment object that contain the magnetic moment, magnetic susceptibility, and magnetic susceptibility times temperature. The columns added are "moment", "moment_err", "chi", "chi_err", "chi_t", and "chi_t_err". The units of these values depend on the values of the mass, eicosane_mass, molecular_weight, and diamagnetic_correction. A record of what scaling was applied is added to the scaling attribute of the DcExperiment object.

Here are the currently supported scaling options:

  • If mass is given but not molecular_weight, the only available scaling is a mass correction.

  • If mass and molecular weight are given, a molar correction is applied. The molar correction can be further modified by giving eicosane_mass and/or diamagnetic_correction.

Parameters:

Name Type Description Default
experiment DcExperiment

A DcExperiment object with a data attribute that has already been processed by add_uncorrected_moment_columns and thus has a column called "uncorrected_moment" and "uncorrected_moment_err".

 required
mass float

mg of sample, by default 0.

 0
eicosane_mass float

mg of eicosane, by default 0.

 0
molecular_weight float

Molecular weight of the material in g/mol, by default 0.

 0
diamagnetic_correction float

Diamagnetic correction of the material in cm^3/mol, by default 0.

 0
Source code in magnetopy\experiments\utils.py 
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def scale_dc_data(
    experiment: DcExperiment,
    mass: float = 0,
    eicosane_mass: float = 0,
    molecular_weight: float = 0,
    diamagnetic_correction: float = 0,
) -> None:
    """Adds columns to the `data` attribute of a `DcExperiment` object that contain
    the magnetic moment, magnetic susceptibility, and magnetic susceptibility times
    temperature. The columns added are `"moment"`, `"moment_err"`, `"chi"`,
    `"chi_err"`, `"chi_t"`, and `"chi_t_err"`. The units of these values depend on
    the values of the `mass`, `eicosane_mass`, `molecular_weight`, and
    `diamagnetic_correction`. A record of what scaling was applied is added to the
    `scaling` attribute of the `DcExperiment` object.

    Here are the currently supported scaling options:

    - If `mass` is given but not `molecular_weight`, the only available scaling is
    a mass correction.

    - If `mass` and `molecular` weight are given, a molar correction is applied. The
    molar correction can be further modified by giving `eicosane_mass` and/or
    `diamagnetic_correction`.

    Parameters
    ----------
    experiment : DcExperiment
        A `DcExperiment` object with a `data` attribute that has already been
        processed by `add_uncorrected_moment_columns` and thus has a column called
        "uncorrected_moment" and "uncorrected_moment_err".
    mass : float, optional
        mg of sample, by default 0.
    eicosane_mass : float, optional
        mg of eicosane, by default 0.
    molecular_weight : float, optional
        Molecular weight of the material in g/mol, by default 0.
    diamagnetic_correction : float, optional
        Diamagnetic correction of the material in cm^3/mol, by default 0.
    """
    mass = mass / 1000  # convert to g
    if mass and molecular_weight:
        experiment.scaling.append("molar")
        if eicosane_mass:
            experiment.scaling.append("eicosane")
        if diamagnetic_correction:
            experiment.scaling.append("diamagnetic_correction")
        mol = mass / molecular_weight
        _scale_magnetic_data_molar_w_eicosane_and_diamagnet(
            experiment.data, mol, eicosane_mass, diamagnetic_correction
        )
    elif mass:
        experiment.scaling.append("mass")
        _scale_magnetic_data_mass(experiment.data, mass)

num_digits_after_decimal(number)

Return the number of digits after the decimal point in a number.

Parameters:

Name Type Description Default
number int | float
required

Returns:

Type Description
int

The number of digits after the decimal point in the number.
Source code in magnetopy\experiments\utils.py 
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def num_digits_after_decimal(number: int | float) -> int:
    """Return the number of digits after the decimal point in a number.

    Parameters
    ----------
    number : int | float

    Returns
    -------
    int
        The number of digits after the decimal point in the number.
    """
    if isinstance(number, int):
        return 0
    return len(str(number).split(".")[1])