Contents

• Introduction
• Main Menu
  • SIM0 GENOME CREATION
  • SIM1 SIMILARITY PERMUTATIONS
  • SIM0 MACHINE LEARNING
  • SIM1 MACHINE LEARNING
  • SIM0 SIM1 COMBINED MACHINE LEARNING
• A step-by-step example

Introduction

This program is designed to simulate permutations of genomes and analyze the results with machine learning algorithms. This system can receive a file containing a series of differential equations, a network flow model, or a boolean network which represents a cell or some other complex system. Once the permutations on this file are created, they are run through a third party program (Matlab, Octave, or R) to record a scalar result for each permutation to be used in standard machine learning models. This process is known as SIM0 and the permutations are referred to as genomes.

In a process known as SIM1, a separate set of permutations can be run on each of the genomes and after analyzing the outputs, a similarity score can be determined between genomes. A similarity matrix is then built up, making it eligible for kernelized machine learning.

The final part of both SIM0 and SIM1 is to perform machine learning with all of the data generated. During this process a chart is generated to show the outcome of each.

All output for this program, including the result of each file for both SIM0 and SIM1, the corresponding similarity and output matrices and the genome files created will be output to a directory chosen by the user.

In order to use this program to generate genome files and get the responses, several requirements must be met. The user must have python version 3.6 installed on their machine. Type python --version on the command line to check. The user also needs the binary of a third party program of their choice (Matlab, Octave, or R) in their path. For example, typing octave on the command line should start that program.

Main Menu

To start the program, simply run the __main__.py class.

python /PATH/TO/__main__.py

The following prompt should come up:

Choose your task:

0: SIM0 - create K genomes
1: SIM1 - create R permutations of K genomes
2: Perform machine learning with existing SIM0 data
3: Perform machine learning with existing SIM1 data
4: Perform machine learning with both SIM0 and SIM1 data
Q: Quit

The necessary necessary inputs and a detailed explanation of the outputs for each menu option are detailed below.

0: SIM0 GENOME CREATION

Genome creation requires 4 inputs: a master SIM0 input file, an integer number of genomes to create, an existing output folder, an expected response type for the files.

The SIM0 master file: This is the file which will have various permutations created from it and must be created by the user. To create it, take a Matlab or R file representing a model of some kind of system which returns a scalar output. Good examples include a process within a cell or a flowering model. This file should have declarations of variables and values within it. For example, in Matlab the line:

global_parameter=0.1;

would be assigning a value of 0.1 to the variable global_parameter. If global_parameter is a value that could be important in determining the scalar output of the final result of a file, or would make a good candidate for a feature in a machine learning model, it can be automatically permuted by using some rendition of the following syntax:

global_parameter=$gauss(.1,.01),name=global_param$;

The explicit value of this variable is instead assigned to a range of variables. In this case, it's a Gaussian spread with a mean of 0.1 and a standard deviation of 0.01.

The supported probability distributions and their parameters are given below:

DISTRIBUTION	SYNTAX	EXAMPLE
discrete	discrete(values...)	$discrete(1,2,3,4),name=discrete_coefficient$
normal/gaussian	gauss(mu,sigma)	$gauss(0,1),name=gaussian_coefficient$
uniform	uniform(min,max)	$uniform(-1,1),name=uniform_coefficient$
gamma	gamma(k,theta)	$gamma(1,.1),name=gamma_coefficient$
log normal	lognormal(mu,theta)	$lognormal(0,1),name=lognormal_coefficient$
binomial	binomial(n,p)	$binomial(100,.5),name=binomial_coefficient$
poisson	poisson(k,lambda)	$poisson(0,1),poisson_coefficient$
boolean (R files only)	boolean(probability_of_zero)	$boolean(.2),name=boolean_coefficient$

These files also support the syntax $val$ and $val,name=coefficient_name$, both of which default to a gaussian distribution with std.deviation .1. For example:

$5$

is the same as writing:

$gauss(5,.1),name=coefficient1$

and

$5,name=gaussian_coefficient$

is the same as writing:

$gauss(5,.1),name=gaussian_coefficient$

Once these important variables have had their explicit declarations replaced with this "dollar sign" syntax, save the file in one of the following formats:

• ".R" for R files
• ".m" for Matlab files
• ".octave" for Octave files (.m files work in Octave, but the file extension allows the program to know which third party program to call).

Number of genomes to create: This value (referred to as K) is the number of permutations to run on the SIM0 master file.

Existing output folder: This value should be a string representing a path that already exists on the users computer. It must be the full path, and does not accept shortcuts for home (~/) in the string itself. A folder named GenomeFiles will be created at this location.

Expected Response Type: This is the expected response type for the genomes created. For SIM0, only "float" (for regressors) and "int" (for classifiers) are supported.

Outputs: SIM0 will create 2K + 2 files, where K is the number of genomes. For each genome there is a version of the original SIM0 master file, with the variables replaced by actual values. So for example:

global_parameter=$gauss(.1,.01),name=global_param$;

might be replaced with:

global_parameter=0.105;

since 0.105 is within reason for the Gaussian distribution with a mean of .1 and a standard deviation of .01. Every $$ syntax in the original file will be replaced with values according to the appropriate distribution, making a file that can be run in the third party program corresponding to the original file extension. These K files are created and run automatically, and their results recorded in a .CSV file called "Sim0Output.csv". There will also be a key file created for each genome file. This key file is just a series of declarations of the assigned variables which will be used in SIM1. Finally, all key files' values are combined into a CSV file called "Sim0GenomesMatrix.csv".

1: SIM1 SIMILARITY PERMUTATIONS

Permutations on existing genomes requires 5 inputs: a master SIM1 input file, an integer number of genomes that were created in SIM0, an integer representing the number of trials to run on each genome, an existing output folder, an expected response type for the files.

The SIM1 master file: This should be a modification of the SIM0 master file except that an entirely different set of variables should be permuted with the $$ syntax, and the original variables that were replaced with their genomic value as determined by SIM0. To do this, load genome_key1 at the top of the file so all those values are defined in scope. Then just replace the original $$ syntax with the originally chosen variable names. For example:

global_parameter=$gauss(.1,.01),name=global_param$;

would be replaced with:

global_parameter=global_param;

where global_param is already defined because genome_key1 was loaded at the top of the file. Then just permute a separate set of variables.

other_coefficient=$discrete(1,2,3,4),name=discrete$

All of the same $$ syntaxes and file types that were supported in SIM0 are also supported for SIM1.

Number of genomes to create: This value (sometimes referred to as K) is the number of genomes that were created in SIM0.

Number of trials to run: This value (sometimes referred to as R) is the number of trials on each genome that should be run. This means R different versions of each new $$ marked variable will be created, and then the genome_key1 will be swapped out K times for each genome. R*K total trial by genome files will be created.

Existing output folder: This value should be a string representing a path that already exists on the users computer. It must be the full path, and does not accept shortcuts for home (~/) in the string itself. A folder named GenomeFiles will be created at this location if it doesn't already exist.

Expected Response Type: This is the expected response type for the genomes created. For SIM1, "float" (for regressors) and "int" (for classifiers) are supported as well as "vector" for vector response types from a third party system. //TODO: details on intricacies of vector responses and how a similarity matrix is made.

Outputs: SIM1 will create R*K + 1 files, where R is the number of trials and K is the number of genomes. Similar to SIM0 all $$ have been replaced with real values, but now "genome_key1" will also have been replaced with "genome_key2" all the way up to k. All of these R*K files are created and run automatically, and their results used to create a similarity matrix. For each genome, the similarity is measured by how many of the R trials return the same result. So if R is 10 and 7 of the trials return the same result when comparing two different genomes, the similarity score for those two genomes will be 0.7. The similarity score is therefore in the range [0,1]. This similarity matrix is automatically saved as a CSV file called "Sim1SimilarityMatrixfinal.csv".

2: SIM0 MACHINE LEARNING

To analyze the results of SIM0, 4 arguments are needed: a file Sim0Output.csv file expressing the third party program results of SIM0, the accompanying Sim0GenomesMatrix file, 'REGRESSION' or 'CLASSIFICATION' for the type of analysis, and a list of indices for categorical features in the Sim0GenomesMatrix.

Once these are submitted, categorical features will be one-hot encoded, splitting them out into individual binary features. Then 3 machine learning algorithms will be run: Random Forest, Support Vector Machines (with linear kernel) and Support Vector Machines (with radial basis function kernel). For all of these, hyperparameters are optimized and the data is split in to training, testing, and validation groups. This will output a graph called MachineLearningMultiBarPlot.png which shows the accuracy of each machine learning model over a range of different training percentages.

3: SIM1 MACHINE LEARNING

To analyze the results of SIM1, 3 arguments are needed: a file Sim0Output.csv file expressing the third party program results of SIM0, a Sim1SimilarityMatrix.csv file, and 'REGRESSION' or 'CLASSIFICATION' for the type of analysis.

Once these are submitted 1 machine learning algorithm will be run: Kernelized Support Vector Machines (with radial basis function kernel). Hyperparameters are optimized and the data is split in to training, testing, and validation groups. This will output a graph called MachineLearningMultiBarPlot.png which shows the accuracy of the machine learning model over a range of different training percentages.

4: SIM0 SIM1 COMBINED MACHINE LEARNING

To analyze the results of SIM0 and SIM1 at the same time, 5 arguments are needed: a file Sim0Output.csv file expressing the third party program results of SIM0, the accompanying Sim0GenomesMatrix file, a Sim1SimilarityMatrix.csv file, and 'REGRESSION' or 'CLASSIFICATION' for the type of analysis, and a list of indices for categorical features in the Sim0GenomesMatrix.

Once these are submitted, categorical features will be one-hot encoded, splitting them out into individual binary features. Then 4 machine learning algorithms will be run: Random Forest, Support Vector Machines (with linear kernel), Support Vector Machines (with radial basis function kernel), and Kernelized Support Vector Machines. For all of these, hyperparameters are optimized and the data is split in to training, testing, and validation groups. This will output a graph called MachineLearningMultiBarPlot.png which shows the accuracy of each machine learning model over a range of different training percentages.

A step-by-step example

Start with SIM0

To use this software the following are needed:

• Python 3
• The Python packages numpy scikit-learn, and matplotlib (which can be installed via pip)
• Matlab, Octave, or R (the program binary should be accessible via the command line e.g. typing "octave" in the command line should open Octave)

The first step is to create a SIM0 master file which can be permuted to create separate genomes. This should be an R, Octave or Matlab file which returns an output based on declared numeric variables. An example of this can be found in the file SimKernModels/Radiation/v4.m.t. Some variables are hard coded while others are surrounded with the "dollar sign" syntax. The second step should be to create an empty output folder. An example of how to run a SIM0 classifier and create 10 genomes is given below:

python __main__.py 0 /path/to/SIM0_MASTER_FILE 10 int /path/to/OUTPUT_FOLDER

If successful, 22 files should now be in this output folder. 10 permuted files of the original Matlab/R/Octave file, 10 key files, a summary of the outputs called "Sim0Output.csv", and the "Sim0GenomesMatrix.csv".

Edit SIM0 Master File to Prepare for SIM1

These 10 permuted files and their corresponding genome_key files can be used for SIM1 analysis. Refactor the original SIM0 master file to instead fetch the newly created "dollar sign" variables from a genome_key file in the same folder. An example of this can be found in SimKernModels/Radiation/v4plus.m.u. Take note how the SIM0 master file (v4.m.t) explicitly declared the variable "RP.ARF_muta" and gives it a binary value. v4plus.m.u however, does not declare this variable and instead imports it from one of the genome key files generated in SIM0. Line 12 explicitly declares ("genome1_key") and any variables defined in that file will be in scope for the v4plus.m.u. As SIM1 loops through genomes, this line will automatically be replaced with the relevant genomes.

The final step in creating a SIM1 master file is to permute another set of variables not used to create genomes in SIM0. The same "dollar sign" syntax will apply.

Run SIM1

When SIM1 runs, it will generate a new set of R permutations (where it replaces the "dollar sign" syntax with values. Then, for every K genome created, make a file using those genomes. The end result is R*K "trial" files with K files using the same genome and R files using the same set of permutations. An example of how to run a SIM1 classifier and permute 10 genomes 20 times is given below:

python __main__.py 1 /path/to/SIM1_MASTER_FILE 10 20 int /path/to/OUTPUT_FOLDER

Note that the 3rd argument passed in must be the number of genomes created in SIM0. If successful, R*K trial files will be created as well as the similarity matrix: "Sim1SimilarityMatrixfinal.csv".

Analyze results

In order to analyze results for SIM0 simply run:

python __main__.py 2 /path/to/Sim0Output.csv /path/to/Sim0GenomesMatrix.csv 'CLASSIFICATION' "0,1,2"

Here the first argument is just the desired menu option, the second argument is the output from SIM0, the third argument is the Sim0GenomesMatrix.csv, the fourth argument is either "CLASSIFICATION" or "REGRESSION" depending on what the original SIM0 master file returned, and the final argument is a comma separated list of categorical variables in Sim0GenomesMatrix.csv. Once this is analyzed a plot will be created in the Sim0GenomesMatrix.csv folder.

In order to analyze results for SIM1 simply run:

python __main__.py 3 /path/to/Sim0Output.csv /path/to/Sim1SimilarityMatrix.csv 'CLASSIFICATION'

Here the first argument is just the desired menu option, the second argument is the output from SIM0, the third argument is the similarity matrix from SIM1, and the final argument is either "CLASSIFICATION" or "REGRESSION" depending on what the original SIM0 master file returned, and the final argument is a comma separated list of categorical variables in Sim0GenomesMatrix.csv. Once this is analyzed a plot will be created in the Sim1SimilarityMatrix.csv folder.

To analyze both SIM0 and SIM1 at the same time run:

python __main__.py 4 /path/to/Sim0Output.csv /path/to/Sim0GenomesMatrix.csv /path/to/Sim1SimilarityMatrix.csv 'CLASSIFICATION' "0,1,2"

Here the first argument is just the desired menu option, the second argument is the output from SIM0, the third argument is the Sim0GenomesMatrix.csv, the fourth argument is the similarity matrix from SIM1, the fifth argument is either 'CLASSIFICATION' or 'REGRESSION', and the final is the list of categorical variables in Sim0GenomesMatrix.csv. Once this is analyzed a plot will be created in the Sim1SimilarityMatrix.csv folder.

SimKern was created by Timo Deist, Andrew Patti, Zhaoqi Wang, David Krane, and Taylor Sorenson, under the supervision of David Craft.

This software utilizes the Python package Matplotlib by Hunter, J.D. Title: Matplotlib: A 2D graphics environment Journal: Computing In Science & Engineering Volume: 9 Number: 3 Pages: 90--95 Matplotlib is a 2D graphics package used for Python for application development, interactive scripting, and publication-quality image generation across user interfaces and operating systems. Publisher: IEEE COMPUTER SOC Year: 2007 DOI: 10.1109/MCSE.2007.55