AI & Data Foundations
A curated entry to legacy machine-learning, deep-learning, and data notes, with explicit coverage gaps and promotion rules.
A curated entry to legacy machine-learning, deep-learning, and data notes, with explicit coverage gaps and promotion rules.
An introductory R guide to expressions, vectors, data structures, control flow, functions, and basic object-oriented systems.
Ordered categories, finite vocabularies, binning, and encoding decisions.
Safe joins, concatenation, cardinality checks, and unmatched-key diagnostics.
A reproducible workflow for normalizing, parsing, validating, and reporting tabular data.
Practical patterns for importing delimited text, spreadsheets, JSON, and native R data while handling common parsing problems.
A path from questions and data-generating processes to reproducible transformations, leakage-resistant splits, distribution-shift evaluation, and bounded conclusions.
A compact vocabulary for discussing datasets, modeling choices, evaluation, and reproducibility without product-specific jargon.
Block target, group, temporal, and preprocessing leakage by defining prediction time, entities, and train-only pipelines.
The labeled two-dimensional table and its core invariants.
Label, position, and MultiIndex selection without ambiguous semantics.
A map from data-generating processes and provenance to leakage-resistant splits, distribution-shift evaluation, and authoritative public sources.
Parsing, time zones, periods, offsets, resampling, and rolling windows in pandas.
Split-apply-combine with explicit output-shape and missing-key decisions.
A map of Jupyter notebooks and JupyterLab, their interactive-computing use cases, and practical learning resources.
A defensive ingestion workflow for tabular files and external data.
A policy-driven approach to detecting, interpreting, and handling missing data.
Start from deployment distribution, splits, metrics, thresholds, and uncertainty instead of treating one test score as universal ability.
A practical NumPy reference covering array creation, indexing, shapes, vectorized operations, aggregation, and array comparison.
A task-oriented map for tabular data work with pandas.
Composable, vectorized patterns and a decision guide for map, apply, agg, transform, and pipe.
Boolean filtering and readable predicates for DataFrames.
A map of the R language, its statistical-computing ecosystem, development environments, major packages, and learning resources.
A guide to pivot, pivot_table, melt, stack, unstack, and explode.
Explicit selection, vectorized operations, mapping, and alignment for Series.
The one-dimensional labeled array at the core of pandas.