sdv 0.17.0.dev0

Synthetic Data Generation for tabular, relational and time series data.

This repository is part of The Synthetic Data Vault Project, a project from DataCebo.

Overview

The Synthetic Data Vault (SDV) is a Synthetic Data Generation ecosystem of libraries that allows users to easily learn single-table, multi-table and timeseries datasets to later on generate new Synthetic Data that has the same format and statistical properties as the original dataset.

Synthetic data can then be used to supplement, augment and in some cases replace real data when training Machine Learning models. Additionally, it enables the testing of Machine Learning or other data dependent software systems without the risk of exposure that comes with data disclosure.

Underneath the hood it uses several probabilistic graphical modeling and deep learning based techniques. To enable a variety of data storage structures, we employ unique hierarchical generative modeling and recursive sampling techniques.

Important Links
:computer: Website	Check out the SDV Website for more information about the project.
:orange_book: SDV Blog	Regular publshing of useful content about Synthetic Data Generation.
:book: Documentation	Quickstarts, User and Development Guides, and API Reference.
:octocat: Repository	The link to the Github Repository of this library.
:scroll: License	The entire ecosystem is published under the MIT License.
:keyboard: Development Status	This software is in its Pre-Alpha stage.
Community	Join our Slack Workspace for announcements and discussions.
Tutorials	Run the SDV Tutorials in a Binder environment.

Current functionality and features:

• Synthetic data generators for single tables with the following features:
  • Using Copulas and Deep Learning based models.
  • Handling of multiple data types and missing data with minimum user input.
  • Support for pre-defined and custom constraints and data validation.
• Synthetic data generators for complex multi-table, relational datasets with the following features:
  • Definition of entire multi-table datasets metadata with a custom and flexible JSON schema.
  • Using Copulas and recursive modeling techniques.
• Synthetic data generators for multi-type, multi-variate timeseries with the following features:
  • Using statistical, Autoregressive and Deep Learning models.
  • Conditional sampling based on contextual attributes.

Try it out now!

If you want to quickly discover SDV, simply click the button below and follow the tutorials!

Join our Slack Workspace

If you want to be part of the SDV community to receive announcements of the latest releases, ask questions, suggest new features or participate in the development meetings, please join our Slack Workspace!

Install

Using pip:

pip install sdv

Using conda:

conda install -c pytorch -c conda-forge sdv

For more installation options please visit the SDV installation Guide

Quickstart

In this short tutorial we will guide you through a series of steps that will help you getting started using SDV.

1. Model the dataset using SDV

To model a multi table, relational dataset, we follow two steps. In the first step, we will load the data and configures the meta data. In the second step, we will use the sdv API to fit and save a hierarchical model. We will cover these two steps in this section using an example dataset.

Step 1: Load example data

SDV comes with a toy dataset to play with, which can be loaded using the sdv.load_demo function:

from sdv import load_demo

metadata, tables = load_demo(metadata=True)

This will return two objects:

1. A Metadata object with all the information that SDV needs to know about the dataset.

For more details about how to build the Metadata for your own dataset, please refer to the Working with Metadata tutorial.

2. A dictionary containing three pandas.DataFrames with the tables described in the metadata object.

The returned objects contain the following information:

{
    'users':
            user_id country gender  age
          0        0     USA      M   34
          1        1      UK      F   23
          2        2      ES   None   44
          3        3      UK      M   22
          4        4     USA      F   54
          5        5      DE      M   57
          6        6      BG      F   45
          7        7      ES   None   41
          8        8      FR      F   23
          9        9      UK   None   30,
  'sessions':
          session_id  user_id  device       os
          0           0        0  mobile  android
          1           1        1  tablet      ios
          2           2        1  tablet  android
          3           3        2  mobile  android
          4           4        4  mobile      ios
          5           5        5  mobile  android
          6           6        6  mobile      ios
          7           7        6  tablet      ios
          8           8        6  mobile      ios
          9           9        8  tablet      ios,
  'transactions':
          transaction_id  session_id           timestamp  amount  approved
          0               0           0 2019-01-01 12:34:32   100.0      True
          1               1           0 2019-01-01 12:42:21    55.3      True
          2               2           1 2019-01-07 17:23:11    79.5      True
          3               3           3 2019-01-10 11:08:57   112.1     False
          4               4           5 2019-01-10 21:54:08   110.0     False
          5               5           5 2019-01-11 11:21:20    76.3      True
          6               6           7 2019-01-22 14:44:10    89.5      True
          7               7           8 2019-01-23 10:14:09   132.1     False
          8               8           9 2019-01-27 16:09:17    68.0      True
          9               9           9 2019-01-29 12:10:48    99.9      True
}

2. Fit a model using the SDV API.

First, we build a hierarchical statistical model of the data using SDV. For this we will create an instance of the sdv.SDV class and use its fit method.

During this process, SDV will traverse across all the tables in your dataset following the primary key-foreign key relationships and learn the probability distributions of the values in the columns.

from sdv import SDV

sdv = SDV()
sdv.fit(metadata, tables)

Once the modeling has finished, you can save your fitted SDV instance for later usage using the save method of your instance.

sdv.save('sdv.pkl')

The generated pkl file will not include any of the original data in it, so it can be safely sent to where the synthetic data will be generated without any privacy concerns.

2. Sample data from the fitted model

In order to sample data from the fitted model, we will first need to load it from its pkl file. Note that you can skip this step if you are running all the steps sequentially within the same python session.

sdv = SDV.load('sdv.pkl')

After loading the instance, we can sample synthetic data by calling its sample method.

samples = sdv.sample()

The output will be a dictionary with the same structure as the original tables dict, but filled with synthetic data instead of the real one.

Finally, if you want to evaluate how similar the sampled tables are to the real data, please have a look at our evaluation framework or visit the SDMetrics library.

Join our community

1. If you would like to see more usage examples, please have a look at the tutorials folder of the repository. Please contact us if you have a usage example that you would want to share with the community.
2. Please have a look at the Contributing Guide to see how you can contribute to the project.
3. If you have any doubts, feature requests or detect an error, please open an issue on github or join our Slack Workspace
4. Also, do not forget to check the project documentation site!

Citation

If you use SDV for your research, please consider citing the following paper:

Neha Patki, Roy Wedge, Kalyan Veeramachaneni. The Synthetic Data Vault. IEEE DSAA 2016.

@inproceedings{
    7796926,
    author={N. {Patki} and R. {Wedge} and K. {Veeramachaneni}},
    booktitle={2016 IEEE International Conference on Data Science and Advanced Analytics (DSAA)},
    title={The Synthetic Data Vault},
    year={2016},
    volume={},
    number={},
    pages={399-410},
    keywords={data analysis;relational databases;synthetic data vault;SDV;generative model;relational database;multivariate modelling;predictive model;data analysis;data science;Data models;Databases;Computational modeling;Predictive models;Hidden Markov models;Numerical models;Synthetic data generation;crowd sourcing;data science;predictive modeling},
    doi={10.1109/DSAA.2016.49},
    ISSN={},
    month={Oct}
}

---

The Synthetic Data Vault Project was first created at MIT's Data to AI Lab in 2016. After 4 years of research and traction with enterprise, we created DataCebo in 2020 with the goal of growing the project. Today, DataCebo is the proud developer of SDV, the largest ecosystem for synthetic data generation & evaluation. It is home to multiple libraries that support synthetic data, including:

• 🔄 Data discovery & transformation. Reverse the transforms to reproduce realistic data.
• 🧠 Multiple machine learning models -- ranging from Copulas to Deep Learning -- to create tabular, multi table and time series data.
• 📊 Measuring quality and privacy of synthetic data, and comparing different synthetic data generation models.

Get started using the SDV package -- a fully integrated solution and your one-stop shop for synthetic data. Or, use the standalone libraries for specific needs.

Release Notes

0.16.0 - 2022-07-21

This release brings user friendly improvements and bug fixes on the SDV constraints, to help users generate their synthetic data easily.

Some predefined constraints have been renamed and redefined to be more user friendly & consistent. The custom constraint API has also been updated for usability. The SDV now automatically determines the best handling_strategy to use for each constraint, attempting transform by default and falling back to reject_sampling otherwise. The handling_strategy parameters are no longer included in the API.

Finally, this version of SDV also unifies the parameters for all sampling related methods for all models (including TabularPreset).

Changes to Constraints

• GreatherThan constraint is now separated in two new constraints: Inequality, which is intended to be used between two columns, and ScalarInequality, which is intended to be used between a column and a scalar.

• Between constraint is now separated in two new constraints: Range, which is intended to be used between three columns, and ScalarRange, which is intended to be used between a column and low and high scalar values.

• FixedIncrements a new constraint that makes the data increment by a certain value.

• New create_custom_constraint function available to create custom constraints.

Removed Constraints

• Rounding Rounding is automatically being handled by the rdt.HyperTransformer.
• ColumnFormula the create_custom_constraint takes place over this one and allows more advanced usage for the end users.

New Features

• Improve error message for invalid constraints - Issue #801 by @fealho
• Numerical Instability in Constrained GaussianCopula - Issue #806 by @fealho
• Unify sampling params for reject sampling - Issue #809 by @amontanez24
• Split GreaterThan constraint into Inequality and ScalarInequality - Issue #814 by @fealho
• Split Between constraint into Range and ScalarRange - Issue #815 @pvk-developer
• Change columns to column_names in OneHotEncoding and Unique constraints - Issue #816 by @amontanez24
• Update columns parameter in Positive and Negative constraint - Issue #817 by @fealho
• Create FixedIncrements constraint - Issue #818 by @amontanez24
• Improve datetime handling in ScalarInequality and ScalarRange constraints - Issue #819 by @pvk-developer
• Support strict boundaries even when transform strategy is used - Issue #820 by @fealho
• Add create_custom_constraint factory method - Issue #836 by @fealho

Internal Improvements

• Remove handling_strategy parameter - Issue #833 by @amontanez24
• Remove fit_columns_model parameter - Issue #834 by @pvk-developer
• Remove the ColumnFormula constraint - Issue #837 by @amontanez24
• Move table_data.copy to base class of constraints - Issue #845 by @fealho

Bugs Fixed

• Numerical Instability in Constrained GaussianCopula - Issue #801 by @tlranda and @fealho
• Fix error message for FixedIncrements - Issue #865 by @pvk-developer
• Fix constraints with conditional sampling - Issue #866 by @amontanez24
• Fix error message in ScalarInequality - Issue #868 by @pvk-developer
• Cannot use max_tries_per_batch on sample: TypeError: sample() got an unexpected keyword argument 'max_tries_per_batch' - Issue #885 by @amontanez24
• Conditional sampling + batch size: ValueError: Length of values (1) does not match length of index (5) - Issue #886 by @amontanez24
• TabularPreset doesn't support new sampling parameters - Issue #887 by @fealho
• Conditional Sampling: batch_size is being set to None by default? - Issue #889 by @amontanez24
• Conditional sampling using GaussianCopula inefficient when categories are noised - Issue #910 by @amontanez24

Documentation Changes

• Show the API for TabularPreset models - Issue #854 by @katxiao
• Update handling constraints doc - Pull Request #856 by @amontanez24
• Update custom costraints documentation - Pull Request #857 by @pvk-developer

0.15.0 - 2022-05-25

This release improves the speed of the GaussianCopula model by removing logic that previously searched for the appropriate distribution to use. It also fixes a bug that was happening when conditional sampling was used with the TabularPreset.

The rest of the release focuses on making changes to improve constraints including changing the UniqueCombinations constraint to FixedCombinations, making the Unique constraint work with missing values and erroring when null values are seen in the OneHotEncoding constraint.

New Features

• Silence warnings coming from univariate fit in copulas - Issue #769 by @pvk-developer
• Remove parameters related to distribution search and change default - Issue #767 by @fealho
• Update the UniqueCombinations constraint - Issue #793 by @fealho
• Make Unique constraint works with nans - Issue #797 by @fealho
• Error out if nans in OneHotEncoding - Issue #800 by @amontanez24

Bugs Fixed

• Unable to sample conditionally in Tabular_Preset model - Issue #796 by @katxiao

Documentation Changes

• Support GPU computing and progress track? - Issue #478 by @fealho

0.14.1 - 2022-05-03

This release adds a TabularPreset, available in the sdv.lite module, which allows users to easily optimize a tabular model for speed. In this release, we also include bug fixes for sampling with conditions, an unresolved warning, and setting field distributions. Finally, we include documentation updates for sampling and the new TabularPreset.

Bugs Fixed

• Sampling with conditions={column: 0.0} for float columns doesn't work - Issue #525 by @shlomihod and @tssbas
• resolved FutureWarning with Pandas replaced append by concat - Issue #759 by @Deathn0t
• Field distributions bug in CopulaGAN - Issue #747 by @katxiao
• Field distributions bug in GaussianCopula - Issue #746 by @katxiao

New Features

• Set default transformer to categorical_fuzzy - Issue #768 by @amontanez24
• Model nulls normally when tabular preset has constraints - Issue #764 by @katxiao
• Don't modify my metadata object - Issue #754 by @amontanez24
• Presets should be able to handle constraints - Issue #753 by @katxiao
• Change preset optimize_for --> name - Issue #749 by @katxiao
• Create a speed optimized Preset - Issue #716 by @katxiao

Documentation Changes

• Add tabular preset docs - Issue #777 by @katxiao
• sdv.sampling module is missing from the API - Issue #740 by @katxiao

0.14.0 - 2022-03-21

This release updates the sampling API and splits the existing functionality into three methods - sample, sample_conditions, and sample_remaining_columns. We also add support for sampling in batches, displaying a progress bar when sampling with more than one batch, sampling deterministically, and writing the sampled results to an output file. Finally, we include fixes for sampling with conditions and updates to the documentation.

Bugs Fixed

• Fix write to file in sampling - Issue #732 by @katxiao
• Conditional sampling doesn't work if the model has a CustomConstraint - Issue #696 by @katxiao

New Features

• Updates to GaussianCopula conditional sampling methods - Issue #729 by @katxiao
• Update conditional sampling errors - Issue #730 by @katxiao
• Enable Batch Sampling + Progress Bar - Issue #693 by @katxiao
• Create sample_remaining_columns() method - Issue #692 by @katxiao
• Create sample_conditions() method - Issue #691 by @katxiao
• Improve sample() method - Issue #690 by @katxiao
• Create Condition object - Issue #689 by @katxiao
• Is it possible to generate data with new set of primary keys? - Issue #686 by @katxiao
• No way to fix the random seed? - Issue #157 by @katxiao
• Can you set a random state for the sdv.tabular.ctgan.CTGAN.sample method? - Issue #515 by @katxiao
• generating different synthetic data while training the model multiple times. - Issue #299 by @katxiao

Documentation Changes

• Typo in the document documentation - Issue #680 by @katxiao

0.13.1 - 2021-12-22

This release adds support for passing tabular constraints to the HMA1 model, and adds more explicit error handling for metric evaluation. It also includes a fix for using categorical columns in the PAR model and documentation updates for metadata and HMA1.

Bugs Fixed

• Categorical column after sequence_index column - Issue #314 by @fealho

New Features

• Support passing tabular constraints to the HMA1 model - Issue #296 by @katxiao
• Metric evaluation error handling metrics - Issue #638 by @katxiao

Documentation Changes

• Make true/false values lowercase in Metadata Schema specification - Issue #664 by @katxiao
• Update docstrings for hma1 methods - Issue #642 by @katxiao

0.13.0 - 2021-11-22

This release makes multiple improvements to different Constraint classes. The Unique constraint can now handle columns with the name index and no longer crashes on subsets of the original data. The Between constraint can now handle columns with nulls properly. The memory of all constraints was also improved.

Various other features and fixes were added. Conditional sampling no longer crashes when the num_rows argument is not provided. Multiple localizations can now be used for PII fields. Scaffolding for integration tests was added and the workflows now run pip check.

Additionally, this release adds support for Python 3.9!

Bugs Fixed

• Gaussian Copula – Memory Issue in Release 0.10.0 - Issue #459 by @xamm
• Applying Unique Constraint errors when calling model.fit() on a subset of data - Issue #610 by @xamm
• Calling sampling with conditions and without num_rows crashes - Issue #614 by @xamm
• Metadata.visualize with path parameter throws AttributeError - Issue #634 by @xamm
• The Unique constraint crashes when the data contains a column called index - Issue #616 by @xamm
• The Unique constraint cannot handle non-default index - Issue #617 by @xamm
• ConstraintsNotMetError when applying Between constraint on datetime columns containing null values - Issue #632 by @katxiao

New Features

• Adds Multi localisations feature for PII fields defined in #308 - PR #609 by @xamm

Housekeeping Tasks

• Support latest version of Faker - Issue #621 by @katxiao
• Add scaffolding for Metadata integration tests - Issue #624 by @katxiao
• Add support for Python 3.9 - Issue #631 by @amontanez24

Internal Improvements

• Add pip check to CI workflows - Issue #626 by @pvk-developer

Documentation Changes

• Anonymizing PII in single table tutorials states address field as e-mail type - Issue #604 by @xamm

Special thanks to @xamm, @katxiao, @pvk-developer and @amontanez24 for all the work that made this release possible!

0.12.1 - 2021-10-12

This release fixes bugs in constraints, metadata behavior, and SDV documentation. Specifically, we added proper handling of data containing null values for constraints and timeseries data, and updated the default metadata detection behavior.

Bugs Fixed

• ValueError: The parameter loc has invalid values - Issue #353 by @fealho
• Gaussian Copula is generating different data with metadata and without metadata - Issue #576 by @katxiao
• Make pomegranate an optional dependency - Issue #567 by @katxiao
• Small wording change for Question Issue Template - Issue #571 by @katxiao
• ConstraintsNotMetError when using GreaterThan constraint with datetime - Issue #590 by @katxiao
• GreaterThan constraint crashing with NaN values - Issue #592 by @katxiao
• Null values in GreaterThan constraint raises error - Issue #589 by @katxiao
• ColumnFormula raises ConstraintsNotMetError when checking NaN values - Issue #593 by @katxiao
• GreaterThan constraint raises TypeError when using datetime - Issue #596 by @katxiao
• Fix repository language - Issue #464 by @fealho
• Update init.py - Issue #578 by @dyuliu
• IndexingError: Unalignable boolean - Issue #446 by @fealho

0.12.0 - 2021-08-17

This release focuses on improving and expanding upon the existing constraints. More specifically, the users can now (1) specify multiple columns in Positive and Negative constraints, (2) use the new Uniqueconstraint and (3) use datetime data with the Between constraint. Additionaly, error messages have been added and updated to provide more useful feedback to the user.

Besides the added features, several bugs regarding the UniqueCombinations and ColumnFormula constraints have been fixed, and an error in the metadata.json for the student_placements dataset was corrected. The release also added documentation for the fit_columns_model which affects the majority of the available constraints.

New Features

• Change default fit_columns_model to False - Issue #550 by @katxiao
• Support multi-column specification for positive and negative constraint - Issue #545 by @sarahmish
• Raise error when multiple constraints can't be enforced - Issue #541 by @amontanez24
• Create Unique Constraint - Issue #532 by @amontanez24
• Passing invalid conditions when using constraints produces unreadable errors - Issue #511 by @katxiao
• Improve error message for ColumnFormula constraint when constraint column used in formula - Issue #508 by @katxiao
• Add datetime functionality to Between constraint - Issue #504 by @katxiao

Bugs Fixed

• UniqueCombinations constraint with handling_strategy = 'transform' yields synthetic data with nan values - Issue #521 by @katxiao and @csala
• UniqueCombinations constraint outputting wrong data type - Issue #510 by @katxiao and @csala
• UniqueCombinations constraint on only one column gets stuck in an infinite loop - Issue #509 by @katxiao
• Conditioning on a non-constraint column using the ColumnFormula constraint - Issue #507 by @katxiao
• Conditioning on the constraint column of the ColumnFormula constraint - Issue #506 by @katxiao
• Update metadata.json for duration of student_placements dataset - Issue #503 by @amontanez24
• Unit test for HMA1 when working with a single child row per parent row - Issue #497 by @pvk-developer
• UniqueCombinations constraint for more than 2 columns - Issue #494 by @katxiao and @csala

Documentation Changes

• Add explanation of fit_columns_model to API docs - Issue #517 by @katxiao

0.11.0 - 2021-07-12

This release primarily addresses bugs and feature requests related to using constraints for the single-table models. Users can now enforce scalar comparison with the existing GreaterThan constraint and apply 5 new constraints: OneHotEncoding, Positive, Negative, Between and Rounding. Additionally, the SDV will now auto-apply constraints for rounding numerical values, and for keeping the data within the observed bounds. All related user guides are updated with the new functionality.

New Features

• Add OneHotEncoding Constraint - Issue #303 by @fealho
• GreaterThan Constraint should apply to scalars - Issue #410 by @amontanez24
• Improve GreaterThan constraint - Issue #368 by @amontanez24
• Add Non-negative and Positive constraints across multiple columns- Issue #409 by @amontanez24
• Add Between values constraint - Issue #367 by @fealho
• Ensure values fall within the specified range - Issue #423 by @amontanez24
• Add Rounding constraint - Issue #482 by @katxiao
• Add rounding and min/max arguments that are passed down to the NumericalTransformer - Issue #491 by @amontanez24

Bugs Fixed

• GreaterThan constraint between Date columns rasises TypeError - Issue #421 by @amontanez24
• GreaterThan constraint's transform strategy fails on columns that are not float - Issue #448 by @amontanez24
• AttributeError on UniqueCombinations constraint with non-strings - Issue #196 by @katxiao
• Use reject sampling to sample missing columns for constraints - Issue #435 by @amontanez24

Documentation Changes

• Ensure privacy metrics are available in the API docs - Issue #458 by @fealho
• Ensure forumla constraint is called ColumnFormula everywhere in the docs - Issue #449 by @fealho

0.10.1 - 2021-06-10

This release changes the way we sample conditions to not only group by the conditions passed by the user, but also by the transformed conditions that result from them.

Issues resolved

• Conditionally sampling on variable in constraint should have variety for other variables - Issue #440 by @amontanez24

0.10.0 - 2021-05-21

This release improves the constraint functionality by allowing constraints and conditions at the same time. Additional changes were made to update tutorials.

Issues resolved

• Not able to use constraints and conditions in the same time - Issue #379 by @amontanez24
• Update benchmarking user guide for reading private datasets - Issue #427 by @katxiao

0.9.1 - 2021-04-29

This release broadens the constraint functionality by allowing for the ColumnFormula constraint to take lambda functions and returned functions as an input for its formula.

It also improves conditional sampling by ensuring that any id fields generated by the model remain unique throughout the sampled data.

The CTGAN model was improved by adjusting a default parameter to be more mathematically correct.

Additional changes were made to improve tutorials as well as fix fragile tests.

Issues resolved

• Tutorials test sometimes fails - Issue #355 by @fealho
• Duplicate IDs when using reject-sampling - Issue #331 by @amontanez24 and @csala
• discriminator_decay should be initialized at 1e-6 but it's 0 - Issue #401 by @fealho and @YoucefZemmouri
• Tutorial typo - Issue #380 by @fealho
• Request for sdv.constraint.ColumnFormula for a wider range of function - Issue #373 by @amontanez24 and @JetfiRex

0.9.0 - 2021-03-31

This release brings new privacy metrics to the evaluate framework which help to determine if the real data could be obtained or deduced from the synthetic samples. Additionally, now there is a normalized score for the metrics, which stays between 0 and 1.

There are improvements that reduce the usage of memory ram when sampling new data. Also there is a new parameter to control the reject sampling crash, graceful_reject_sampling, which if set to True and if it's not possible to generate all the requested rows, it will just issue a warning and return whatever it was able to generate.

The Metadata object can now be visualized using different combinations of names and details, which can be set to True or False in order to display only the table names with details or without. There is also an improvement on the validation, which now will display all the errors found at the end of the validation instead of only the first one.

This version also exposes all the hyperparameters of the models CTGAN and TVAE to allow a more advanced usage. There is also a fix for the TVAE model on small datasets and it's performance with NaN values has been improved. There is a fix for when using UniqueCombinationConstraint with the transform strategy.

Issues resolved

• Memory Usage Gaussian Copula Trained Model consuming high memory when generating synthetic data - Issue #304 by @pvk-developer and @AnupamaGangadhar
• Add option to visualize metadata with only table names - Issue #347 by @csala
• Add sample parameter to control reject sampling crash - Issue #343 by @fealho
• Verbose metadata validation - Issue #348 by @csala
• Missing the introduction of custom specification for hyperparameters in the TVAE model - Issue #344 by @imkhoa99 and @pvk-developer

0.8.0 - 2021-02-24

This version adds conditional sampling for tabular models by combining a reject-sampling strategy with the native conditional sampling capabilities from the gaussian copulas.

It also introduces several upgrades on the HMA1 algorithm that improve data quality and robustness in the multi-table scenarios by making changes in how the parameters of the child tables are aggregated on the parent tables, including a complete rework of how the correlation matrices are modeled and rebuild after sampling.

Issues resolved

• Fix probabilities contain NaN error - Issue #326 by @csala
• Conditional Sampling for tabular models - Issue #316 by @fealho and @csala
• HMA1: LinAlgError: SVD did not converge - Issue #240 by @csala

0.7.0 - 2021-01-27

This release introduces a few changes in the HMA1 relational algorithm to decrease modeling and sampling times, while also ensuring that correlations are properly kept across tables and also adding support for some relational schemas that were not supported before.

A few changes in constraints and tabular models also ensure that situations that produced errors before now work without errors.

Issues resolved

• Fix unique key generation - Issue #306 by @fealho
• Ensure tables that contain nothing but ids can be modeled - Issue #302 by @csala
• Metadata visualization improvements - Issue #301 by @csala
• Multi-parent re-model and re-sample issue - Issue #298 by @csala
• Support datetimes in GreaterThan constraint - Issue #266 by @rollervan
• Support for multiple foreign keys in one table - Issue #185 by @csala

0.6.1 - 2020-12-31

SDMetrics version is updated to include the new Time Series metrics, which have also been added to the API Reference and User Guides documentation. Additionally, a few code has been refactored to reduce external dependencies and a few minor bugs related to single table constraints have been fixed

Issues resolved

• Add timeseries metrics and user guides - Issue #289 by @csala
• Add functions to generate regex ids - Issue #288 by @csala
• Saving a fitted tabular model with UniqueCombinations constraint raises PicklingError - Issue #286 by @csala
• Constraints: handling_strategy='reject_sampling' causes 'ZeroDivisionError: division by zero' - Issue #285 by @csala

0.6.0 - 2020-12-22

This release updates to the latest CTGAN, RDT and SDMetrics libraries to introduce a new TVAE model, multiple new metrics for single table and multi table, and fixes issues in the re-creation of tabular models from a metadata dict.

Issues resolved

• Upgrade to SDMetrics v0.1.0 and add sdv.metrics module - Issue #281 by @csala
• Upgrade to CTGAN 0.3.0 and add TVAE model - Issue #278 by @fealho
• Add dtype_transformers to Table.from_dict - Issue #276 by @csala
• Fix Metadata from_dict behavior - Issue #275 by @csala

0.5.0 - 2020-11-25

This version updates the dependencies and makes a few internal changes in order to ensure that SDV works properly on Windows Systems, making this the first release to be officially supported on Windows.

Apart from this, some more internal changes have been made to solve a few minor issues from the older versions while also improving the processing speed when processing relational datasets with the default parameters.

API breaking changes

• The distribution argument of the GaussianCopula has been renamed to field_distributions.
• The HMA1 and SDV classes now use the categorical_fuzzy transformer by default instead of the one_hot_encoding one.

Issues resolved

• GaussianCopula: rename distribution argument to field_distributions - Issue #237 by @csala
• GaussianCopula: Improve error message if an invalid distribution name is passed - Issue #220 by csala
• Import urllib.request explicitly - Issue #227 by @csala
• TypeError: cannot astype a datetimelike from [datetime64[ns]] to [int32] - Issue #218 by @csala
• Change default categorical transformer to categorical_fuzzy in HMA1 - Issue #214 by @csala
• Integer categoricals being sampled as strings instead of integer values - Issue #194 by @csala

0.4.5 - 2020-10-17

In this version a new family of models for Synthetic Time Series Generation is introduced under the sdv.timeseries sub-package. The new family of models now includes a new class called PAR, which implements a Probabilistic AutoRegressive model.

This version also adds support for composite primary keys and regex based generation of id fields in tabular models and drops Python 3.5 support.

Issues resolved

• Drop python 3.5 support - Issue #204 by @csala
• Support composite primary keys in tabular models - Issue #207 by @csala
• Add the option to generate string id fields based on regex on tabular models - Issue #208 by @csala
• Synthetic Time Series - Issue #142 by @csala

0.4.4 - 2020-10-06

This version adds a new tabular model based on combining the CTGAN model with the reversible transformation applied in the GaussianCopula model that converts random variables with arbitrary distributions to new random variables with standard normal distribution.

The reversible transformation is handled by the GaussianCopulaTransformer recently added to RDT.

Issues resolved

• Add CopulaGAN Model - Issue #202 by @csala

0.4.3 - 2020-09-28

This release moves the models and algorithms related to generation of synthetic relational data to a new sdv.relational subpackage (Issue #198)

As part of the change, also the old sdv.models have been removed and now relational model is based on the recently introduced sdv.tabular models.

0.4.2 - 2020-09-19

In this release the sdv.evaluation module has been reworked to include 4 different metrics and in all cases return a normalized score between 0 and 1.

Included metrics are:

• cstest
• kstest
• logistic_detection
• svc_detection

0.4.1 - 2020-09-07

This release fixes a couple of minor issues and introduces an important rework of the User Guides section of the documentation.

Issues fixed

• Error Message: "make sure the Graphviz executables are on your systems' PATH" - Issue #182 by @csala
• Anonymization mappings leak - Issue #187 by @csala

0.4.0 - 2020-08-08

In this release SDV gets new documentation, new tutorials, improvements to the Tabular API and broader python and dependency support.

Complete list of changes:

• New Documentation site based on the pydata-sphinx-theme.
• New User Guides and Notebook tutorials.
• New Developer Guides section within the docs with details about the SDV architecture, the ecosystem libraries and how to extend and contribute to the project.
• Improved API for the Tabular models with focus on ease of use.
• Support for Python 3.8 and the newest versions of pandas, scipy and scikit-learn.
• New Slack Workspace for development discussions and community support.

0.3.6 - 2020-07-23

This release introduces a new concept of Constraints, which allow the user to define special relationships between columns that will not be handled via modeling.

This is done via a new sdv.constraints subpackage which defines some well-known pre-defined constraints, as well as a generic framework that allows the user to customize the constraints to their needs as much as necessary.

New Features

• Support for Constraints - Issue #169 by @csala

0.3.5 - 2020-07-09

This release introduces a new subpackage sdv.tabular with models designed specifically for single table modeling, while still providing all the usual conveniences from SDV, such as:

• Seamless multi-type support
• Missing data handling
• PII anonymization

Currently implemented models are:

• GaussianCopula: Multivariate distributions modeled using copula functions. This is stronger version, with more marginal distributions and options, than the one used to model multi-table datasets.
• CTGAN: GAN-based data synthesizer that can generate synthetic tabular data with high fidelity.

0.3.4 - 2020-07-04

New Features

• Support for Multiple Parents - Issue #162 by @csala
• Sample by default the same number of rows as in the original table - Issue #163 by @csala

General Improvements

• Add benchmark - Issue #165 by @csala

0.3.3 - 2020-06-26

General Improvements

• Use SDMetrics for evaluation - Issue #159 by @csala

0.3.2 - 2020-02-03

General Improvements

• Improve metadata visualization - Issue #151 by @csala @JDTheRipperPC

0.3.1 - 2020-01-22

New Features

• Add Metadata Validation - Issue #134 by @csala @JDTheRipperPC

• Add Metadata Visualization - Issue #135 by @JDTheRipperPC

General Improvements

• Add path to metadata JSON - Issue #143 by @JDTheRipperPC

• Use new Copulas and RDT versions - Issue #147 by @csala @JDTheRipperPC

0.3.0 - 2019-12-23

New Features

• Create sdv.models subpackage - Issue #141 by @JDTheRipperPC

0.2.2 - 2019-12-10

New Features

• Adapt evaluation to the different data types - Issue #128 by @csala @JDTheRipperPC

• Extend load_demo functionality to load other datasets - Issue #136 by @JDTheRipperPC

0.2.1 - 2019-11-25

New Features

• Methods to generate Metadata from DataFrames - Issue #126 by @csala @JDTheRipperPC

0.2.0 - 2019-10-11

New Features

• compatibility with rdt issue 72 - Issue #120 by @csala @JDTheRipperPC

General Improvements

• Error docstring sampler.__fill_text_columns - Issue #144 by @JDTheRipperPC
• Reach 90% coverage - Issue #112 by @JDTheRipperPC
• Review unittests - Issue #111 by @JDTheRipperPC

Bugs Fixed

• Time required for sample_all function? - Issue #118 by @csala @JDTheRipperPC

0.1.2 - 2019-09-18

New Features

• Add option to model the amount of child rows - Issue 93 by @ManuelAlvarezC

General Improvements

• Add Evaluation Metrics - Issue 52 by @ManuelAlvarezC

• Ensure unicity on primary keys on different calls - Issue 63 by @ManuelAlvarezC

Bugs fixed

• executing readme: 'not supported between instances of 'int' and 'NoneType' - Issue 104 by @csala

0.1.1 - Anonymization of data

• Add warnings when trying to model an unsupported dataset structure. GH#73
• Add option to anonymize data. GH#51
• Add support for modeling data with different distributions, when using GaussianMultivariate model. GH#68
• Add support for VineCopulas as a model. GH#71
• Improve GaussianMultivariate parameter sampling, avoiding warnings and unvalid parameters. GH#58
• Fix issue that caused that sampled categorical values sometimes got numerical values mixed. GH#81
• Improve the validation of extensions. GH#69
• Update examples. GH#61
• Replaced Table class with a NamedTuple. GH#92
• Fix inconsistent dependencies and add upper bound to dependencies. GH#96
• Fix error when merging extension in Modeler.CPA when running examples. GH#86

0.1.0 - First Release

• First release on PyPI.