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ADVXYZ
| This procedure converts from (a,d,v) sky coordinates to (x,y,z) pixel coordinates in a data cube. It is a wrapper to ad2xy in the IDL Astronomy User's Library, which does not handle 3D data. |

ANNEAL__DEFINE
| The anneal class performs simulated annealing to maximize a fitness function. This is a little different than normal, where annealing minimizes a penalty (or energy) function. Simulated annealing maximizes a function by taking random ... |

APCON
| This function returns the values of many different constants used in astrophysics. |

APPEND
| This function appends a second array to a first one. It's only real convenience is that it handles the case when the first array is undefined. |

ARR_EQ
| This function compares 2 arrays, and returns 1 if all of their values are equal. |

ARRGEN
| This function is similar to (and an extension of) built-in functions like indgen, findgen, etc. It creates an array given the first element, last element, and step size. It can create arrays which increase/decrease by constant amounts... |

ASSERT
| This procedure is a simple routine to check assumptions during programming. If, at any time, an assertion fails to be true, the program halts with an error message. |

BLACKBODY
| This function calculates the Planck function I_nu or I_lambda. I_nu = 2h nu^3 c^-2 ( exp(h nu / kT) -1)^-1 I_lambda = 2h c^2 lambda^-5 (exp ( hc / lambda kt) -1)^-1 |

BORDER_INDICES
| This function calculates and returns the (1D) indices corresponding to the borders of an array. These indices can be conerted back into n_dimensional indices via array_indices. |

BRACKET
| This procedure attempts to bracket the minimum of a one dimensional function. A minimum is bracketed by three points ax, bx, cx, if: 1) bx is between ax and cx 2) f(b) < f(a) and f(b) < f(c) In this situation, provided the function... |

BRENT
| This function minimizes a function of one variable. The function requires 3 input abscissas which bracket at least one local minimum (see, e.g. bracket.pro) The algorithm is adapted from Numerical Recipes, but is substantially modifie... |

CAUCHY
| This function returns the probability density function of a Cauchy distribution, with median mu and width gamma, evaluated at x. |

CNB_COVAR
| This function computes the covariance matrix for a set of multidimensional data. It optionally returns the principal axes, of the distribution, along with the variance along each principal axis. The principal axes and variances descri... |

CNB_IMF
| This function both evaluates the IMF at given mass, and returns masses drawn at random from the IMF. The functional form of the IMF is given by dN/dM ~ M^-alpha, where alpha = 0 for 0 < M / Msolar < .07 (Allen et al 2005) = 1.05 fo... |

CNB_PCA
| This procedure calculates the principal components of a dataset. Many IDL routines do this, but I don't really understand their idiosyncrasies. In particular, the builtin PCOMP has weird outputs, and chokes whin n_dim >> 1, n_dim &... |

CNB_VOIGT
| This function computes centered Voigt profiles. It is a wrapper to the builtin IDL VOIGT routine, which uses a somewhat confusing variable convention. The Voigt function implemented here is a stright convolution of a Gaussian with a L... |

CURL
| This procedure computes the curl of a 3d vector field sampled on a uniform grid. |

DENSITYMAP
| This procedure creates a smoothed map of the suface density of objects on the sky or in a plane. |

DETECTOUTLIER
| Plot which objects were flagged as outliers from detectoutlier. |

DISTRIBUTION__DEFINE
| The distribution class is an interface for objects dealing with probability distributions. |

DIV
| This function calculates the divergence of a 1, 2, or 3-dimensional vector function sampled on a uniform grid. |

DS9REG__DEFINE
| Defines a simple IDL structure to represent a DS9-style region description. Used in conjunction with write_ds9reg |

EDF
| This procedure calculates the empirical distribution function (edf) of a set of data, evaluated at each input data point. The edf is the empirical equivalent of the cumulative distribution function. |

EDF_STATS
| This function calculates a variety of statistics to characterize the discrepancy between 1D data and a model for the distribution from which the data were drawn. Each statistic is based on the empirical distribution function (i.e. the... |

EXTAST3
| This program is a wrapper procedure to the extast routine in the IDL astronomy user's library. extast3 is designed to handle data cubes, which extast cannot handle. This procedure is used by sky2pix to convert between sky and pixel co... |