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Input Steps

Convert raw data to measure’s internal format

step_measure_input_wide()
Ingest Measurements in Separate Columns
step_measure_input_long()
Ingest Measurements from a Single Column

Processing Steps

Apply spectral preprocessing transformations

step_measure_savitzky_golay()
Savitzky-Golay Pre-Processing
step_measure_snv()
Standard Normal Variate (SNV) Transformation
step_measure_msc()
Multiplicative Scatter Correction (MSC)
step_measure_map()
Apply a Custom Function to Measurements

Multi-Channel Operations

Align, combine, and compute ratios between measurement channels

step_measure_channel_align()
Align Multiple Channels to a Common Grid
step_measure_channel_combine()
Combine Multiple Channels
step_measure_channel_ratio()
Compute Ratios Between Channels

Spectral Math

Mathematical transformations for spectral data

step_measure_absorbance()
Convert Transmittance to Absorbance
step_measure_transmittance()
Convert Absorbance to Transmittance
step_measure_log()
Log Transformation
step_measure_kubelka_munk()
Kubelka-Munk Transformation
step_measure_derivative()
Simple Finite Difference Derivatives
step_measure_derivative_gap()
Gap (Norris-Williams) Derivatives

Region Operations

Trim, exclude, and resample measurement regions

step_measure_trim()
Trim Measurements to Specified Range
step_measure_exclude()
Exclude Measurement Ranges
step_measure_resample()
Resample Measurements to New Grid
step_measure_interpolate()
Interpolate Gaps in Measurement Data

Sample-wise Normalization

Normalize each spectrum independently

step_measure_normalize_auc()
Normalize by Area Under Curve
step_measure_normalize_istd()
Internal Standard Normalization
step_measure_normalize_max()
Normalize by Maximum Value
step_measure_normalize_peak()
Normalize to a Specific Peak Region
step_measure_normalize_range()
Normalize to Range 0-1
step_measure_normalize_sum()
Normalize by Sum (Total Intensity)
step_measure_normalize_vector()
Normalize by L2 (Euclidean) Norm

Variable-wise Scaling

Scale across samples at each measurement location

step_measure_center()
Mean Centering
step_measure_scale_auto()
Auto-Scaling (Z-Score Normalization)
step_measure_scale_pareto()
Pareto Scaling
step_measure_scale_range()
Range Scaling
step_measure_scale_vast()
VAST Scaling (Variable Stability Scaling)

Reference-Based Corrections

Blank subtraction and reference corrections

step_measure_subtract_blank()
Subtract Blank Measurement
step_measure_subtract_reference()
Subtract or Divide by Reference Spectrum
step_measure_ratio_reference()
Compute Ratio to Reference Spectrum

Calibration

X-axis and Y-axis calibration steps

step_measure_calibrate_x()
Apply X-Axis Calibration
step_measure_calibrate_y()
Apply Y-Axis Calibration (Response Factor)

Output Steps

Convert internal format back to modeling-ready data

step_measure_output_wide()
Reorganize Measurements to Separate Columns
step_measure_output_long()
Reorganize Measurements to Long Format

Peak Operations

Peak detection, integration, and analysis for chromatography

step_measure_peaks_detect()
Detect Peaks in Measurements
step_measure_peaks_integrate()
Integrate Peak Areas
step_measure_peaks_filter()
Filter Peaks by Criteria
step_measure_peaks_deconvolve()
Deconvolve Overlapping Peaks
step_measure_peaks_to_table()
Convert Peaks to Tidy Table
is_peaks_list()
Test if object is a peaks list
find_peaks_cols()
Find peaks columns in a data frame

Smoothing & Noise Reduction

Noise reduction and spike removal steps

step_measure_smooth_ma()
Moving Average Smoothing
step_measure_smooth_median()
Median Filter Smoothing
step_measure_smooth_gaussian()
Gaussian Kernel Smoothing
step_measure_smooth_wavelet()
Wavelet Denoising
step_measure_filter_fourier()
Fourier Low-Pass Filtering
step_measure_despike()
Remove Spikes and Outliers from Measurements

Alignment & Registration

Spectral alignment and shift correction

step_measure_align_shift()
Shift Alignment via Cross-Correlation
step_measure_align_reference()
Align to Reference Spectrum
step_measure_align_dtw()
Dynamic Time Warping Alignment
step_measure_align_ptw()
Parametric Time Warping Alignment
step_measure_align_cow()
Correlation Optimized Warping Alignment

Quality Control

Quality metrics and data cleaning

step_measure_qc_snr()
Calculate Signal-to-Noise Ratio
step_measure_qc_saturated()
Detect Saturated Measurements
step_measure_qc_outlier()
Detect Outlier Samples
step_measure_impute()
Impute Missing Values in Measurements

Tunable Parameters

Parameters for hyperparameter tuning with dials

window_side() differentiation_order()
Parameter for measure steps
baseline_lambda() baseline_asymmetry() baseline_degree() baseline_half_window() baseline_span()
Parameters for baseline correction steps
peak_location_min() peak_location_max()
Parameters for peak normalization
derivative_order() derivative_gap() derivative_segment()
Parameters for derivative steps
smooth_window() smooth_sigma() fourier_cutoff() despike_threshold()
Parameters for smoothing steps
align_max_shift() align_segment_length()
Parameters for alignment steps
outlier_threshold()
Parameters for quality control steps
bin_width() emsc_degree() osc_n_components()
Parameters for feature engineering and scatter correction

Data

Included datasets for examples and testing

meats_long
Fat, water and protein content of meat samples
glucose_bioreactors bioreactors_large bioreactors_small
Raman Spectra Bioreactor Data
hplc_chromatograms
Simulated HPLC Chromatography Data
sec_chromatograms
Simulated SEC/GPC Chromatography Data
sec_calibration
SEC/GPC Calibration Standards Summary
maldi_spectra
Simulated MALDI-TOF Mass Spectrometry Data

Baseline Correction

Baseline correction steps and utilities

step_measure_baseline_airpls()
Adaptive Iteratively Reweighted Penalized Least Squares Baseline
step_measure_baseline_als()
Asymmetric Least Squares (ALS) Baseline Correction
step_measure_baseline_arpls()
Asymmetrically Reweighted Penalized Least Squares Baseline Correction
step_measure_baseline_auto()
Automatic Baseline Correction Method Selection
step_measure_baseline_custom()
Custom Baseline Correction with User-Provided Function
step_measure_baseline_gpc() superseded
GPC/SEC Baseline Correction
step_measure_baseline_minima()
Local Minima Interpolation Baseline Correction
step_measure_baseline_morph()
Iterative Morphological Baseline Correction
step_measure_baseline_poly()
Polynomial Baseline Correction
step_measure_baseline_py()
Python-Based Baseline Correction via pybaselines
step_measure_baseline_rf()
Robust Fitting Baseline Correction
step_measure_baseline_rolling()
Rolling Ball Baseline Correction
step_measure_baseline_snip()
SNIP Baseline Correction
step_measure_baseline_tophat()
Top-Hat Morphological Baseline Correction
step_measure_detrend()
Remove Trend from Measurements
subtract_rf_baseline()
Subtract baseline using robust fitting method

SEC/GPC Analysis

Molecular weight calculations for size exclusion chromatography

step_measure_mw_averages() superseded
Calculate Molecular Weight Averages for SEC/GPC
step_measure_mw_distribution() superseded
Generate Molecular Weight Distribution Curve
step_measure_mw_fractions() superseded
Calculate Molecular Weight Fractions for SEC/GPC

Feature Engineering

Extract features from spectral data

step_measure_integrals()
Calculate Region Integrals
step_measure_ratios()
Calculate Region Ratios
step_measure_moments()
Calculate Statistical Moments
step_measure_bin()
Spectral Binning

Extended Scatter Correction

Advanced scatter correction methods

step_measure_emsc()
Extended Multiplicative Scatter Correction (EMSC)
step_measure_osc()
Orthogonal Signal Correction (OSC)

Data Augmentation

Training data augmentation for improved model robustness

step_measure_augment_noise()
Add Random Noise to Measurements
step_measure_augment_shift()
Add Random X-axis Shifts
step_measure_augment_scale()
Random Intensity Scaling

Drift & Batch Correction

Correct for signal drift and batch effects

step_measure_drift_qc_loess()
QC-Based Drift Correction Using LOESS
step_measure_drift_linear()
Linear Drift Correction
step_measure_drift_spline()
Spline-Based Drift Correction
step_measure_qc_bracket()
QC Bracketing Interpolation
step_measure_batch_reference()
Reference-Based Batch Correction
measure_detect_drift()
Detect Drift in Analytical Data

Calibration & Quantitation

Calibration curves, LOD/LOQ, and quantitation

measure_calibration measure_calibration-class
Calibration Curve Object
measure_calibration_fit()
Fit a Calibration Curve
measure_calibration_predict()
Predict Concentrations from Calibration Curve
measure_calibration_verify()
Verify Calibration Curve Performance
is_measure_calibration()
Test if Object is a Calibration Curve
tidy(<measure_calibration>) tidy(<measure_calibration_verify>)
Tidy a Calibration Curve
glance(<measure_calibration>)
Glance at Calibration Curve Summary
augment(<measure_calibration>)
Augment Calibration Data
measure_lod()
Calculate Limit of Detection (LOD)
measure_loq()
Calculate Limit of Quantitation (LOQ)
measure_lod_loq()
Calculate LOD and LOQ Together
tidy(<measure_lod>)
Tidy LOD/LOQ Results

Precision & Accuracy

Method validation for precision and accuracy

measure_repeatability()
Repeatability (Within-Run Precision)
measure_intermediate_precision()
Intermediate Precision (Between-Run Precision)
measure_reproducibility()
Reproducibility (Between-Lab Precision)
measure_gage_rr()
Gage R&R (Measurement System Analysis)
measure_accuracy()
Accuracy Assessment
measure_linearity()
Linearity Assessment
measure_carryover()
Carryover Assessment

Uncertainty

ISO GUM uncertainty budgets

measure_uncertainty_budget()
Create an Uncertainty Budget
measure_uncertainty()
Quick Uncertainty Calculation
uncertainty_component()
Create an Uncertainty Component
uncertainty_type_a()
Create Type A Uncertainty from Repeated Measurements
uncertainty_type_b_rectangular()
Create Type B Uncertainty from Rectangular Distribution
uncertainty_type_b_expanded()
Create Type B Uncertainty from Expanded Uncertainty
tidy(<measure_uncertainty_budget>)
Tidy an Uncertainty Budget

Control Charts & QC

Statistical process control and system suitability

measure_control_limits()
Calculate Control Limits
measure_control_chart()
Generate Control Chart
measure_system_suitability()
System Suitability Check

Method Comparison

Compare analytical methods using Bland-Altman, Deming, and Passing-Bablok

measure_bland_altman()
Bland-Altman Method Comparison
measure_deming_regression()
Deming Regression for Method Comparison
measure_passing_bablok()
Passing-Bablok Regression for Method Comparison
measure_proficiency_score()
Proficiency Testing Scores

Matrix Effects & Sample Prep

Matrix effect quantification, standard addition, and sample prep QC

measure_matrix_effect()
Matrix Effect Analysis
step_measure_standard_addition()
Standard Addition Correction
step_measure_dilution_correct()
Dilution Factor Correction
step_measure_surrogate_recovery()
Surrogate/Internal Standard Recovery

Criteria & Assessment

Acceptance criteria and pass/fail evaluation

criterion()
Create an Acceptance Criterion
measure_criteria()
Create a Set of Acceptance Criteria
measure_assess()
Assess Data Against Acceptance Criteria
all_pass()
Check if All Criteria Pass
get_failures()
Extract Failed Criteria
criteria_bioanalytical() criteria_ich_q2() criteria_bland_altman() criteria_method_comparison() criteria_proficiency_testing() criteria_matrix_effects() criteria_surrogate_recovery()
Preset Acceptance Criteria

Metadata Validation

Validate analytical metadata columns

measure_validate_metadata()
Validate Analytical Metadata
measure_standardize_sample_type()
Standardize Sample Type Values
measure_sample_types
Canonical Sample Types

Multi-Way Analysis

PARAFAC, Tucker, and MCR-ALS decomposition for multi-dimensional data

step_measure_parafac()
PARAFAC Decomposition for Multi-Dimensional Data
step_measure_tucker()
Tucker Decomposition for Multi-Dimensional Data
step_measure_mcr_als()
MCR-ALS Decomposition for Multi-Dimensional Data

Multi-Dimensional Data

Support for 2D and higher-dimensional measurement data (LC-DAD, EEM, 2D NMR)

new_measure_nd_tbl()
Create a new n-dimensional measure tibble
new_measure_nd_list()
Create a new n-dimensional measure list
is_measure_nd_tbl()
Test if object is an n-dimensional measure tibble
is_measure_nd_list()
Test if object is an n-dimensional measure list
measure_ndim()
Get the number of dimensions of a measurement
measure_dim_names()
Get dimension names of an n-dimensional measurement
measure_dim_units()
Get dimension units of an n-dimensional measurement
measure_is_regular()
Check if an n-dimensional measurement has a regular grid
measure_grid_info()
Get grid information for an n-dimensional measurement
measure_apply()
Apply a function to measurement data along dimensions
measure_unfold()
Unfold n-dimensional measurement to 1D
measure_fold()
Fold 1D measurement back to n-dimensional
measure_slice()
Extract slices from n-dimensional measurement
measure_project()
Project n-dimensional measurement by aggregating across dimensions
find_measure_nd_cols()
Find n-dimensional measure columns in a data frame
get_measure_col_ndim()
Get the dimensionality of a measure column

Utilities

Helper functions and utilities

Technique Pack Registry

Registration and discovery for technique packs

measure_packs()
List Registered Technique Packs
measure_steps()
List Available Steps
register_measure_pack()
Register a Technique Pack
register_measure_step()
Register a Step from a Technique Pack

Exploration & Analysis

Interactive exploration and summary functions for prototyping

measure_map()
Apply a Function to Each Sample's Measurements
measure_map_safely()
Apply a Function Safely to Each Sample's Measurements
measure_summarize()
Summarize Measurements Across Samples

Data Organization

Column detection and role assignment helpers

measure_identify_columns()
Identify Column Types in Analytical Data
measure_column_summary()
Get Column Summary by Type
measure_column_patterns
Common column naming patterns for analytical data
set_measure_roles()
Set Measure Roles in a Recipe
check_measure_recipe()
Check Measure Recipe Structure

Axis Validation

Axis semantics and data quality validation

validate_measure()
Validate measure data
measure_axis_info()
Get axis information from measure data
infer_axis_type()
Infer axis type from location values
check_axis_consistency()
Check axis consistency across samples
measure_quality_summary()
Summarize measure data quality

Validation Reporting

Generate reproducible analytical method validation reports

measure_validation_report()
Create an Analytical Method Validation Report
render_validation_report()
Render a Validation Report to Document Format
has_validation_section()
Check if validation report has a section
get_validation_section()
Get validation section data
add_validation_section()
Add or update a validation section
print(<measure_validation_report>)
Print a Validation Report
summary(<measure_validation_report>)
Summarize a Validation Report
tidy(<measure_validation_report>)
Tidy a Validation Report

Visualization & Diagnostics

Plotting and diagnostic functions for measure data

autoplot(<measure_tbl>) autoplot(<measure_list>) autoplot(<recipe>)
Autoplot Methods for Measure Objects
autoplot(<measure_bland_altman>)
Plot Bland-Altman Analysis
autoplot(<measure_calibration>)
Plot Calibration Curve Diagnostics
autoplot(<measure_control_chart>)
Plot Control Chart
autoplot(<measure_deming_regression>) autoplot(<measure_passing_bablok>)
Plot Method Comparison Regression
autoplot(<measure_linearity>)
Plot Linearity Assessment Results
autoplot(<measure_matrix_effect>)
Plot Matrix Effects
autoplot(<measure_proficiency_score>)
Plot Proficiency Test Scores
autoplot(<measure_uncertainty_budget>)
Plot Uncertainty Budget
fortify(<measure_tbl>) fortify(<measure_list>)
Convert Measure Objects to Data Frames for Plotting
fortify(<measure_calibration>)
Extract Calibration Curve Data
plot_measure_comparison()
Compare Multiple Preprocessing Recipes
measure_plot_summary()
Plot Summary Statistics for Measure Data