| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments: value-axis
Returns the value of the range-bottom property of
a value-axis
. The value
may be set at creation time by passing
the range-bottom
initarg, or any
time later by calling (setf range-bottom).
A value to use for the low end of a value-axis
in a chart-widget
. The value should be a real
number, or else nil
to have the value
computed automatically. The default value
is nil
.
When the value is a number, it should typically be less than or equal to the smallest data value that is being charted, or at least lower than the smallest value that you are interested in viewing at the moment.
When the value is computed automatically, a relatively "round" number is chosen that is equal to or somewhat less than the smallest data value. If set-chart-value is later called to add a value that is less than the current automatically computed range bottom, then a new range bottom will be computed to encompass the new value.
The value should be less than the range-top. To make the values increase in the atypical direction, use invert-axis rather than a range-bottom that is greater than the range-top.
To force a new range bottom to be computed (when the value of this
property is nil
), call update-chart-widget. This may be useful to
recompute the range after set-chart-value has been used to modify values
so that the data range is smaller, or if something has changed to
cause the widget's chart-value-returner function to return a
different range of values.
See also major-tic-increment and minor-tics-per-major-tic.
See chart-widget
and also cg-chart-widget.htm.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |