fuelcell.visuals

Data visualization methods

fuelcell.visuals.build_axlabel(base, units)

Generate axis label

Auxilliary function to generate an axis label from the specified name and units: ‘Base [units]’

Parameters

• base (str) – Axis name

• units (str) – Axis units

Returns

Complete axis label

Return type

label

fuelcell.visuals.check_errs(errs, df, err_name, err_col)

Check if data set contains error data and return valid error data

Auxilliary function to check if the given data set contains data that can be used to draw error bars. Returns the error values if possible, otherwise returns an array of zeros.

Parameters

• errs (bool) – Whether data set should be checked for error data. If False, an array of zeros is returned.

• df (DataFrame) – DataFrame that should contain error data

• err_name (str) – String of the form ‘[datatype]_std’ (ex: ‘current_std’). Used to parse column labels of df

• err_col (int or str) – Index or label of the column containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

Returns

err – Array of values which can be used to draw error bars. If valid error values could not be found, an array of zeros of the same length as df is returned

Return type

numpy array

fuelcell.visuals.fig_saver(export_name, export_type='png')

Save the current figure

Auxilliary function to save the current figure as an image.

export_name: str, path object, or file-like

File name to save the image as. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

export_type: str (default=’png’)

File type to save the image as. Only used if export_name does not include the file type

fuelcell.visuals.plot_cp_raw(data=None, use_all=False, fig=None, ax=None, labels=None, line=False, scatter=True, errs=False, current_column=2, potential_column=1, time_column=0, err_column=(4, 5), xunits='s', yunits=('V', 'mA'), export_name=None, export_type='png', fig_kw={}, err_kw={}, **plot_kw)

Plot raw chronopotentiometry data

Note: it is strongly reccomended to use this function with data from only a single test and the default values of line, scatter, and errs to avoid overplotting.

Parameters

• data (Datum object(default=None)) – Datum object containing CP data

• labels (array-like (default=None)) – List of labels to be used in the legend. If unspecified, keys of data are used as labels.

• line (bool (default=True)) – Whether to draw a line connecting the individual data points

• scatter (bool (default=False)) – Whether to draw a marker at each data point

• errs (bool (default=False)) – Whether to include an error bar at each data point

• current_column (int or str (default=2)) – Index or label of the column containing current data. Used only if automatic column identification fails

• potential_column (int or str (default=1)) – Index or label of the column containing potential data. Used only if automatic column identification fails

• time_column (int or str (default=0)) – Index or label of the column containing time data. Used only if automatic column identification fails

• err_column (tuple or list of int or str (default=(4,5))) – Indices or labels of the columns containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

• xunits (str (default=r'$mA/cm^2$')) – Units of the x-axis

• yunits (tuple or list of str (default=('ma','V'))) – Units of the y-axis

• export_name (str, path object, or file-like (default=None)) – If specified, the figure will be saved as an image. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

• export_type (str (default='png')) – File type to save the image as. Only used if export_name is specified and export_name does not include the file type

• fig_kw (dict) – Dict with keywords passed to the plt.subplots function to create the figure

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

Returns

• fig (Figure) – Figure object containing all plot elements

• ax (Tuple) – Tuple of axes objects containing the plotted data

fuelcell.visuals.plot_cv(data=None, use_all=False, fig=None, ax=None, labels=None, line=True, scatter=False, errs=False, current_column=1, potential_column=0, err_column=3, xunits='V', yunits='$mA/cm^2$', export_name=None, export_type='png', fig_kw={}, err_kw={}, **plot_kw)

Plot cyclic voltammetry data

Parameters

• data (Datum object(default=None)) – Datum object containing CV data

• labels (array-like (default=None)) – List of labels to be used in the legend. If unspecified, keys of data are used as labels.

• line (bool (default=True)) – Whether to draw a line connecting the individual data points

• scatter (bool (default=False)) – Whether to draw a marker at each data point

• errs (bool (default=False)) – Whether to include an error bar at each data point

• current_column (int or str (default=1)) – Index or label of the column containing current data. Used only if automatic column identification fails

• potential_column (int or str (default=0)) – Index or label of the column containing potential data. Used only if automatic column identification fails

• err_column (int or str (default=3)) – Index or label of the column containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

• xunits (str (default='V')) – Units of the x-axis

• yunits (str (default=r'$mA/cm^2$')) – Units of the y-axis

• export_name (str, path object, or file-like (default=None)) – If specified, the figure will be saved as an image. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

• export_type (str (default='png')) – File type to save the image as. Only used if export_name is specified and export_name does not include the file type

• fig_kw (dict) – Dict with keywords passed to the plt.subplots function to create the figure

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

Returns

• fig (Figure) – Figure object containing all plot elements

• ax (Axes) – Axes object containing the plotted data

fuelcell.visuals.plot_eis(data=None, use_all=False, fig=None, ax=None, labels=None, line=False, scatter=True, errs=False, current_column=0, potential_column=1, err_column=3, xunits='$R_{Re} [\\Omega]$', yunits='$R_{Im} [\\Omega]$', export_name=None, export_type='png', fig_kw={}, **plot_kw)

Plot electrochemical impedance spectroscopy data

Parameters

• data (Datum object(default=None)) – Datum object containing EIS data

• labels (array-like (default=None)) – List of labels to be used in the legend. If unspecified, keys of data are used as labels.

• line (bool (default=True)) – Whether to draw a line connecting the individual data points

• scatter (bool (default=False)) – Whether to draw a marker at each data point

• errs (bool (default=False)) – Whether to include an error bar at each data point

• current_column (int or str (default=1)) – Index or label of the column containing current data. Used only if automatic column identification fails

• potential_column (int or str (default=0)) – Index or label of the column containing potential data. Used only if automatic column identification fails

• err_column (int or str (default=3)) – Index or label of the column containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

• xunits (str (default='V')) – Units of the x-axis

• yunits (str (default=r'$mA/cm^2$')) – Units of the y-axis

• export_name (str, path object, or file-like (default=None)) – If specified, the figure will be saved as an image. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

• export_type (str (default='png')) – File type to save the image as. Only used if export_name is specified and export_name does not include the file type

• fig_kw (dict) – Dict with keywords passed to the plt.subplots function to create the figure

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

Returns

• fig (Figure) – Figure object containing all plot elements

• ax (Axes) – Axes object containing the plotted data

fuelcell.visuals.plot_lsv(data=None, use_all=False, fig=None, ax=None, labels=None, line=False, scatter=True, errs=False, current_column=1, potential_column=2, err_column=3, xunits='V', yunits='$mA/cm^2$', export_name=None, export_type='png', fig_kw={}, **plot_kw)

Plot linear sweep voltammetry data

Parameters

• data (Datum object(default=None)) – Datum object containing LSV data

• labels (array-like (default=None)) – List of labels to be used in the legend. If unspecified, keys of data are used as labels.

• line (bool (default=True)) – Whether to draw a line connecting the individual data points

• scatter (bool (default=False)) – Whether to draw a marker at each data point

• errs (bool (default=False)) – Whether to include an error bar at each data point

• current_column (int or str (default=1)) – Index or label of the column containing current data. Used only if automatic column identification fails

• potential_column (int or str (default=0)) – Index or label of the column containing potential data. Used only if automatic column identification fails

• err_column (int or str (default=3)) – Index or label of the column containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

• xunits (str (default='V')) – Units of the x-axis

• yunits (str (default=r'$mA/cm^2$')) – Units of the y-axis

• export_name (str, path object, or file-like (default=None)) – If specified, the figure will be saved as an image. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

• export_type (str (default='png')) – File type to save the image as. Only used if export_name is specified and export_name does not include the file type

• fig_kw (dict) – Dict with keywords passed to the plt.subplots function to create the figure

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

Returns

• fig (Figure) – Figure object containing all plot elements

• ax (Axes) – Axes object containing the plotted data

fuelcell.visuals.plotter(ax, x, y, e, l, line, scatter, errs, err_kw, **plot_kw)

Plot data

Auxilliary function to plot the specified data

Parameters

• ax (Axes) – Axes object on which to plot the data

• x (array-like) – x values

• y (array-like) – y values

• e (array-like) – Error values used to draw error bars

• l (array-like) – Labels to be used in the legend

• line (bool) – Whether to draw a line connecting the individual data points

• scatter (bool) – Whether to draw a marker at each data point

• errs (bool) – Whether to include an error bar at each data point

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

fuelcell.visuals.polcurve(data=None, use_all=False, fig=None, ax=None, labels=None, line=True, scatter=True, errs=False, current_column=0, potential_column=1, err_column=3, xunits='$mA/cm^2$', yunits='V', export_name=None, export_type='png', fig_kw={}, err_kw={}, **plot_kw)

Plot polarization curves using chronopotentiometry or chronoamperometry data

Parameters

• data (Datum object(default=None)) – Datum object containing CP or CA data

• labels (array-like (default=None)) – List of labels to be used in the legend. If unspecified, keys of data are used as labels.

• line (bool (default=True)) – Whether to draw a line connecting the individual data points

• scatter (bool (default=False)) – Whether to draw a marker at each data point

• errs (bool (default=False)) – Whether to include an error bar at each data point

• current_column (int or str (default=0)) – Index or label of the column containing current data. Used only if automatic column identification fails

• potential_column (int or str (default=1)) – Index or label of the column containing potential data. Used only if automatic column identification fails

• err_column (int or str (default=3)) – Index or label of the column containing data to draw error bars. Used only if automatic column identification fails. Ignored if errs=False

• xunits (str (default=r'$mA/cm^2$')) – Units of the x-axis

• yunits (str (default='V')) – Units of the y-axis

• export_name (str, path object, or file-like (default=None)) – If specified, the figure will be saved as an image. Can either be a complete file path to save the image in a specific directory or a file name to save the image in the current directory

• export_type (str (default='png')) – File type to save the image as. Only used if export_name is specified and export_name does not include the file type

• fig_kw (dict) – Dict with keywords passed to the plt.subplots function to create the figure

• err_kw (dict) – Dict with keywords passed to the plt.errorbars function used to draw errorbars

• **plot_kw – all remaining keyword arguments are passed to the plt.plot or plt.scatter function used to draw the graphs

Returns

• fig (Figure) – Figure object containing all plot elements

• ax (Axes) – Axes object containing the plotted data