## vbars prefab

Version 2.32
Prefabs

Manual page for vbars_prefab(PL)

View the vbars prefab examples

`vbars` is a prefab for producing bar graphs with vertical solid bars for one or two groups.`` Error bars may be added above or below the bar graph, or error bars alone may be rendered (error bar amounts must be precomputed with this prefab).``

Note that several of the other prefabs produce bar graphs.`` For chronological-based data use the chron prefab.`` The compare prefab computes means and SD on the fly, and graphs them.``

## Parameters

Prefab parameter name | Data type | Default | Description | Examples (ignore line wrapping)
Standard parameters |  |  | All of the standard prefab parameters may be used. You must specify data (the name of the input data file).
x | data field | must be specified | Identifies the data field that will hold X component. By default these are assumed to be categories, but thay can be continuous numeric values if the xnumeric parameter is specified. | `x=2 x=pmb`
y y2 | data field | y must be specified | Identifies the data field(s) that will hold Y component. Data must be numeric. If y and y2 are specified, two sets of bars will be produced. | `y=3 y=cfr y2=cfl`
err err2 | data field |  | Identifies the data field(s) that will hold error amount, such as SD. Data must be numeric. | `err=4 err=cfr_sd err2=cfl_sd`
color color2 | color | `orange, powderblue` | Color of bars. | `color=green`
barwidth | inches or cm or `line` | based on data | Specifies the width of the filled bars. May be given as `line` to produce very thin bars. The default bar width is not always appropriate. | `barwidth=0.05 barwidth=line`
errcolor errcolor2 | color | `black` | Color of error bars. | `errcolor=gray(0.4)`
errwidth | inches or cm or `line` | 0.08 " | Width of error bar tails. | `errwidth=0.1`
errthick | line thickness value | 0.5 | The thickness of the error bar lines (default = 0.5) | `errthick=1`
erroneway | `yes` or `no` | `no` | Draw one-way upward error bars instead of the usual symmetrical error bars. Old name: errunder | `erroneway=yes`
erronly | `yes` or `no` | `no` | If `yes`, render error bars only. y will control the location of the center of the bar and err will control the error amount. | `erronly=yes`
xnumeric | `yes` or `no` | `no` | If `yes`, signifies that X values are numeric rather than categories. | `xnumeric=yes`
vals | `yes` or `no` | `no` | If `yes`, display numeric values near the top of each bar. | `vals=yes`
crossover | Y value |  | A value in Y where bars begin to point downward instead of upward. For instance, `crossover=0` is often useful when dealing with financial income, to show loss using downward bars. | `crossover=0`
curve order | `yes` or linedetails |  | Generate a moving average curve fit to the bars. It will be drawn behind the bars. Not applicable to a second set of bars. order is an attitional parameter may be set to the number of preceding data points to be considered when computing averages (default = 5). | `curve=yes "curve= color=blue"`
sep | inches or cm | 0.15 " | Controls bar separation when two bar sets are being rendered. | `sep=0.08`

data display engine
Copyright Steve Grubb

Markup created by unroff 1.0, `` `` August 23, 2005.