# Compute x-Axis Tickmark Locations by Time

### Description

Compute x-axis tickmarks like `axTicks`

in base
but with respect to time. Additionally the first
argument is the object indexed by time which you
are looking to derive tickmark locations for.

It is possible to specify the detail you are seeking,
or by passing 'auto' to the `ticks.on`

argument,
to get a best heuristic fit.

### Usage

1 2 3 | ```
axTicksByTime(x, ticks.on='auto', k = 1,
labels=TRUE, format.labels=TRUE, ends=TRUE,
gt = 2, lt = 30)
``` |

### Arguments

`x` |
the object indexed by time, or a vector of times/dates |

`ticks.on` |
what to break on |

`k` |
frequency of breaks |

`labels` |
should a labeled vector be returned |

`format.labels` |
format labels - may be format to use |

`ends` |
should the ends be adjusted |

`gt` |
lower bound on number of breaks |

`lt` |
upper bound on number of breaks |

### Details

This function is written for internal use, and documented for those wishing to use outside of the internal function uses. In general it is most unlikely that the end user will call this function directly.

The format.labels allows for standard formatting like
that used in `format`

, `strptime`

, and `strftime`

.

### Value

A vector of index points to break on, possibly with the index names.

### Author(s)

Jeffrey A. Ryan

### See Also

`endpoints`

### Examples

1 2 3 4 | ```
data(sample_matrix)
axTicksByTime(as.xts(sample_matrix),'auto')
axTicksByTime(as.xts(sample_matrix),'weeks')
axTicksByTime(as.xts(sample_matrix),'months',7)
``` |