profkern {denpro} | R Documentation |

Given a data matrix, returns a level set tree of a kernel estimate, when the dimension of the estimate is less or equal to 4.

profkern(dendat, h, N, Q, cvol=TRUE, ccen=TRUE, cfre=FALSE, kernel="epane", compoinfo=FALSE, trunc=3, threshold=0.0000001, sorsa="crc",hw=NULL)

`dendat` |
n*d data matrix; d<=4 |

`h` |
positive real number or vector of positive real numbers; smoothing parameters from the largest to the smallest |

`N` |
d-vector of dyadic integers >=4; number of knots for every direction: kernel estimate will be evaluated on these knots |

`Q` |
positive integer; number of quantization levels |

`cvol` |
TRUE or FALSE; TRUE if one wants that the volumes of the separated parts of the level sets are returned, note that one needs the volumes for drawing a volume plot |

`ccen` |
T or F; TRUE if one wants that the barycenters of the separated parts of the level sets are returned, note that one needs the barycenters for drawing a barycenter plot |

`cfre` |
T or F; TRUE if one wants that the frequencies for separated parts of the level sets are returned (not implemented) |

`kernel` |
either "epane" or "gauss"; the kernel of the kernel estimate |

`compoinfo` |
TRUE or FALSE; whether definitions of separated regions of level sets will be returned |

`trunc` |
positive real number; truncation of the Gaussian kernel to the interval [-trunc,trunc] |

`threshold` |
positive real number; kernel will be truncated to 0 if the value is smaller than the threshold (not implemented) |

`sorsa` |
if not "crc" uses slower R code |

`hw` |
lower level parameter |

Returns a list of level set trees: for each value of h the level set tree of the corresponding kernel estimate. If h is not a vector but scalar, then only one level set tree will be returned. The level set tree is a list of vectors. The elements of the vectors supply information for each node of the tree. Below we denote with "nodenum" the number of nodes of the tree.

`parent` |
"nodenum"-vector of integers in the range 0,..., nodenum-1; links to the parent of each node. Root nodes are marked with 0. |

`level` |
"nodenum"-vector of positive real numbers; level of the level set from which the set corresponding to the node is a part of. |

`volume` |
"nodenum"-vector of positive real numbers; volumes of sets corresponding to each node |

`center` |
d*nodenum-matrix; barycenters of sets corresponding to each node |

`invalue` |
"nodenum"-vector of positive integers; level of the level set in terms of original frequencies (these values are not normalized so that the estimate would integrate to one |

`component` |
Will be returned if "compoinfo"=TRUE; for each node of the level set a tree pointer to "AtomlistAtom" |

`AtomlistAtom` |
Will be returned if "compoinfo"=TRUE; pointers to "index" |

`AtomlistNext` |
Will be returned if "compoinfo"=TRUE; pointers which define the list of atoms for each separated component (for each node of the level set tree) |

`index` |
Will be returned if "compoinfo"=TRUE; matrix with d columns: determines a knot of the multivariate grid where estimate was evaluated |

`nodefrek` |
"nodenum"-vector of positive integers; number of observations in the set corresponding to the node. This is useful in cluster analysis applications. (Not implemented.) |

Applies the DynaDecompose algorithm, described in the article "Algorithms for manipulation of level sets of nonparametric density estimates", by Jussi Klemela

Jussi Klemela

set.seed(1) dendat<-matrix(rnorm(20),10) # 10*2 data-matrix pk<-profkern(dendat,h=1,N=c(8,8),Q=4) plotvolu(pk) dendat<-sim.data(n=200,type="mulmod") pk<-profkern(dendat,h=1,N=c(64,64),Q=30) plotvolu(pk)

[Package *denpro* version 0.9.0 Index]