spikecomp {Hmisc} | R Documentation |

## spikecomp

### Description

Compute Elements of a Spike Histogram

### Usage

```
spikecomp(
x,
method = c("tryactual", "simple", "grid"),
lumptails = 0.01,
normalize = TRUE,
y,
trans = NULL,
tresult = c("list", "segments", "roundeddata")
)
```

### Arguments

`x` |
a numeric variable |

`method` |
specifies the binning and output method. The default is |

`lumptails` |
the quantile to use for lumping values into a single left and a single right bin for two of the methods. When outer quantiles using |

`normalize` |
set to |

`y` |
a vector of frequencies corresponding to |

`trans` |
a list with three elements: the name of a transformation to make on |

`tresult` |
applies only to |

### Details

Derives the line segment coordinates need to draw a spike histogram. This is useful for adding elements to `ggplot2`

plots and for the `describe`

function to construct spike histograms. Date/time variables are handled by doing calculations on the underlying numeric scale then converting back to the original class. For them the left endpoint of the first bin is taken as the minimal data value instead of rounded using `pretty()`

.

### Value

when `y`

is specified, a list with elements `x`

and `y`

. When `method='tryactual'`

the returned value depends on `tresult`

. For `method='grid'`

, a list with elements `x`

and `y`

and scalar element `roundedTo`

containing the typical bin width. Here `x`

is a character string.

### Author(s)

Frank Harrell

### Examples

```
spikecomp(1:1000)
spikecomp(1:1000, method='grid')
## Not run:
On a data.table d use ggplot2 to make spike histograms by country and sex groups
s <- d[, spikecomp(x, tresult='segments'), by=.(country, sex)]
ggplot(s) + geom_segment(aes(x=x, y=y1, xend=x, yend=y2, alpha=I(0.3))) +
scale_y_continuous(breaks=NULL, labels=NULL) + ylab('') +
facet_grid(country ~ sex)
## End(Not run)
```

*Hmisc*version 5.1-3 Index]