## NAME

d.vect.chart - Displays charts of GRASS vector data in the active frame on the graphics monitor

## KEYWORDS

display

## SYNOPSIS

d.vect.chart
d.vect.chart help
d.vect.chart [-c] map=name [type=string[,string,...]] [layer=integer] [ctype=string] columns=string[,string,...] [sizecol=string] [size=integer] [scale=float] [ocolor=string] [colors=string[,string,...]] [max_ref=float[,float,...]]

### Flags:

-c
  Center the bar chart around a data point

### Parameters:

map=name
  Name of input vector map
type=string[,string,...]
  Type
  Options: point,line,boundary,centroid,area
  Default: point,line,boundary,centroid
layer=integer
  Layer number
  Default: 1
ctype=string
  Chart type
  Options: pie,bar
  Default: pie
columns=string[,string,...]
  Attribute columns containing data
sizecol=string
  Column used for pie chart size
size=integer
  Size of chart (diameter for pie, total width for bar)
  Default: 40
scale=float
  Scale for size (to get size in pixels)
  Default: 1
ocolor=string
  Outline color
  Default: black
colors=string[,string,...]
  Colors used to fill charts
max_ref=float[,float,...]
  Maximum value used for bar plot reference

## DESCRIPTION

d.vect.chart displays charts for GRASS vector data in the active frame on the graphics monitor.

## NOTES

The charts are positioned as follows:

- vector points: on point position
- vector lines: on line centers
- vector areas: on area centroids

Bar charts are placed with their lower edge starting from the y-coordinate of the feature being symbolized, and centered with respect to the x-coordinate. The -c flag can be used to center the bar chart in both x and y directions.
The 'sizecol' parameter is proportionate to the radius.
The optional max_ref parameter accepts a list of values that represent the maximum value for each column listed in the values for the parameter columns. These values are used to create a framed bar plot if ctype is bar (See Example 2).

## EXAMPLES

### Example 1

    d.vect.chart map=vectmap columns=cens51,cens61,cens71,cens81

### Example 2

Create framed bar graphs of an erodibiliy index from the SPEARFISH dataset.

    r.to.vect -s -v in=erode.index out=erode_index feature=area
    v.extract in=erode_index out=erode_index_ctrds type=centroid
    d.rast aspect
    d.vect.chart map=erode_index_ctrds ctype=bar columns=cat \
                 size=10 max_ref=12 scale=1.5 colors=yellow
    d.vect erode_index_ctrds icon=basic/circle fcol=black col=black size=5

Example screenshot (zoomed):

## SEE ALSO

d.erase, d.vect, d.what.vect, d.rast

## AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

Last changed: $Date: 2006/02/07 21:27:08 $

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