# bc.twocomp

### Description

Implementation of two component models. In the two component unconstrained model, the components of the control and case mixtures are the same; however the mixture probabilities may differ for cases and controls. In the two component constrained model, all controls are distributed according to one of the two components while cases follow a mixture distribution of the two components.

### Usage

1 2 3 | ```
bc.twocomp(x.cases, x.controls, constrained = T, lambda.bounds = c(-5, 5),
control.comp = 1, start.vals=NULL)
``` |

### Arguments

`x.cases` |
a numeric vector of case values |

`x.controls` |
a numeric vector of control values |

`constrained` |
Boolean indicating whether the two component constrained model should be used (default |

`lambda.bounds` |
numeric vector of bounds: |

`control.comp` |
indicator of which component contains the controls (1 or 2) |

`start.vals` |
starting values for the EM algorithm. If |

### Value

`lambda` |
Box-Cox transformation parameter |

`type` |
model type ( "2cc" or "2cu") |

`mu.cases` |
means of the Box-Cox transformed case components |

`sig.cases` |
standard deviations of the Box-Cox transformed case components |

`pi.cases` |
proportion of cases in each case component |

`mu.controls` |
means of the Box-Cox transformed control components |

`sig.controls` |
standard deviations of the Box-Cox transformed control components |

`pi.controls` |
proportion of controls in each control component (always equal to 1 for 2cc since all controls are forced into one component) |

`max.loglike` |
the maximum log likelihood value for the model |

`mu.cases.unt` |
an estimate of the untransformed means of the case components. Based on Monte Carlo simulations. Values will differ by computer seed. |

`sig.cases.unt` |
an estimate of the untransformed standard deviations of the case components. Based on Monte Carlo simulations. Values will differ by computer seed. |

`mu.controls.unt` |
an estimate of the untransformed means of the control components. Based on Monte Carlo simulations. Values will differ by computer seed. |

`sig.controls.unt` |
an estimate of the untransformed standard deviations of the control components. Based on Monte Carlo simulations. Values will differ by computer seed. |

`case` |
original case values |

`control` |
original control values |

`time` |
running time for the model fit |

### Author(s)

Michelle Winerip, Garrick Wallstrom, Joshua LaBaer

### See Also

`bc.binorm`

`bc.fourcomp`

`em.twocomp.m1`

`em.twocomp.m2`

`em.twocomp.m3`