topolow2.0.1 package

Force-Directed Euclidean Embedding of Dissimilarity Data

adaptive_MC_sampling

Perform Adaptive Monte Carlo Sampling

add_noise_bias

Add Noise and Bias to Matrix Data

analyze_network_structure

Calculate Network Analysis Metrics

calculate_annual_distances

Calculate Annual Distance Metrics

calculate_cumulative_distances

Calculate Cumulative Distance Metrics

calculate_diagnostics

Calculate Adaptive Monte Carlo Sampling Diagnostics

calculate_prediction_interval

Calculate prediction interval for distance estimates

calculate_procrustes_difference

Calculate Procrustes Difference Between Maps

calculate_procrustes_significance

Calculate Statistical Significance Between Maps Using Procrustes Analy...

calculate_weighted_marginals

Calculate Weighted Marginal Distributions

check_gaussian_convergence

Check Multivariate Gaussian Convergence

clean_data

Clean Data by Removing MAD-based Outliers

color_palettes

Color Palettes

coordinates_to_matrix

Convert coordinates to distance matrix

create_and_optimize_RACMACS_map

Create and Optimize a RACMACS Map

create_base_theme

Create Base Theme

create_cv_folds

Create Cross-validation Folds for Distance Matrix

create_diagnostic_plots

Create Diagnostic Plots for Multiple Chains

create_topolow_map

Main TopoLow algorithm implementation

detect_outliers_mad

Detect Outliers Using Median Absolute Deviation

dist_to_titer_table

Convert Distance Matrix to Titer Panel Format

error_calculator_comparison

Calculate comprehensive error metrics between predicted and true dista...

find_mode

Find Mode of Density Distribution

generate_complex_data

Generate Complex High-Dimensional Data for Testing

generate_kde_samples

Generate New Parameter Samples Using KDE

generate_synthetic_datasets

Generate Synthetic Distance Matrices with Missing Data

generate_unique_string

Generate unique string identifiers with year suffix

get_grid

Create Grid Around Maximum Likelihood Estimate

ggsave_white_bg

Save ggplot with white background

gmultiple

Sigmoid transform function for threshold handling

increase_na_percentage

Increase Missing Values in a Matrix

initial_parameter_optimization

Run Parameter Optimization Via Latin Hypercube Sampling

likelihood_function

Evaluate Likelihood with Cross-Validation

log_transform_parameters

Log Transform Parameter Samples

long_to_matrix

Convert Long Format Data to Distance Matrix

make_interactive

Create Interactive Plot

new_aesthetic_config

Plot Aesthetic Configuration Class

new_annotation_config

Plot Annotation Configuration Class

new_dim_reduction_config

Dimension Reduction Configuration Class

new_layout_config

Plot Layout Configuration Class

only_virus_vs_as

Filter matrix to only virus vs antiserum distances

parameter_sensitivity_analysis

Parameter Sensitivity Analysis

plot_3d_mapping

Create 3D Visualization

plot_cluster_mapping

Create Clustered Mapping Plots

plot_distance_heatmap

Plot Distance Matrix Heatmap

plot_network_structure

Plot Network Structure Analysis

plot_temporal_mapping

Create Temporal Mapping Plot

plot.parameter_sensitivity

Plot Method for Parameter Sensitivity Analysis

plot.profile_likelihood

Plot Method for Profile Likelihood Objects

plot.topolow_amcs_diagnostics

Plot Method for Adaptive Monte Carlo Sampling Diagnostics

plot.topolow_convergence

Plot Method for Convergence Diagnostics

prepare_heatmap_data

Generate Distance Matrix Heatmap Data

print.parameter_sensitivity

Print Method for Parameter Sensitivity Objects

print.profile_likelihood

Print Method for Profile Likelihood Objects

print.topolow_amcs_diagnostics

Print Method for Adaptive Monte Carlo Sampling Diagnostics

print.topolow_convergence

Print Method for Convergence Diagnostics

print.topolow

Print method for topolow objects

process_antigenic_data

Process Raw Antigenic Assay Data

process_distance_matrix

Process distance matrix for convergence error calculations

profile_likelihood_result

Profile Likelihood Analysis Results Class

profile_likelihood

Profile Likelihood Analysis

prune_distance_network

Prune Distance Data for Network Quality

reduce_dimensions

Perform Dimension Reduction

run_adaptive_sampling

Run Adaptive Monte Carlo Sampling

sample_from_distribution

Sample from Weighted Distribution

save_plot

Save Plot to File

scale_to_original_distances

Scale Reduced Dimensions to Match Original Distances

scatterplot_fitted_vs_true

Plot Fitted vs True Distances

summary.topolow

Summary method for topolow objects

symmetric_to_nonsymmetric_matrix

Convert distance matrix to assay panel format

topolow-package

Latin Hypercube and Adaptive Monte Carlo Sampling Functions

unweighted_kde

Unweighted Kernel Density Estimation

validate_antigenic_data

Validate Antigenic Dataset

validate_topolow_df

Validate Input Data Frame

vectorized_process_distance_matrix

Vectorized Processing of Distance Matrix for Convergence Error Calcula...

weighted_kde

Weighted Kernel Density Estimation

yy_to_yyyy

Convert 2-digit to 4-digit year

A robust implementation of Topolow algorithm. It embeds objects into a low-dimensional Euclidean space from a matrix of pairwise dissimilarities, even when the data do not satisfy metric or Euclidean axioms. The package is particularly well-suited for sparse, incomplete, and censored (thresholded) datasets such as antigenic relationships. The core is a physics-inspired, gradient-free optimization framework that models objects as particles in a physical system, where observed dissimilarities define spring rest lengths and unobserved pairs exert repulsive forces. The package also provides functions specific to antigenic mapping to transform cross-reactivity and binding affinity measurements into accurate spatial representations in a phenotype space. Key features include: * Robust Embedding from Sparse Data: Effectively creates complete and consistent maps (in optimal dimensions) even with high proportions of missing data (e.g., >95%). * Physics-Inspired Optimization: Models objects (e.g., antigens, landmarks) as particles connected by springs (for measured dissimilarities) and subject to repulsive forces (for missing dissimilarities), and simulates the physical system using laws of mechanics, reducing the need for complex gradient computations. * Automatic Dimensionality Detection: Employs a likelihood-based approach to determine the optimal number of dimensions for the embedding/map, avoiding distortions common in methods with fixed low dimensions. * Noise and Bias Reduction: Naturally mitigates experimental noise and bias through its network-based, error-dampening mechanism. * Antigenic Velocity Calculation (for antigenic data): Introduces and quantifies "antigenic velocity," a vector that describes the rate and direction of antigenic drift for each pathogen isolate. This can help identify cluster transitions and potential lineage replacements. * Broad Applicability: Analyzes data from various objects that their dissimilarity may be of interest, ranging from complex biological measurements such as continuous and relational phenotypes, antibody-antigen interactions, and protein folding to abstract concepts, such as customer perception of different brands. Methods are described in the context of bioinformatics applications in Arhami and Rohani (2025a) <doi:10.1093/bioinformatics/btaf372>, and mathematical proofs and Euclidean embedding details are in Arhami and Rohani (2025b) <doi:10.48550/arXiv.2508.01733>.

  • Maintainer: Omid Arhami
  • License: BSD_3_clause + file LICENSE
  • Last published: 2025-08-31