NAME
Tk::LogScale - A logarithmic Scale widget
SYNOPSIS
use Tk::LogScale;
$scale = $mw->LogScale(...);DESCRIPTION
This is a Scale widget which uses a logarithmic scale for the position of the thumb.
OPTIONS
Tk::LogScale roughly uses the same options as in Tk::Scale. The -digits option is not implemented. For the -bigincrement and -resolution, translated values have to be used. The -variable option can only be used if the Tie::Watch module is installed (Note: Tie::Watch is in the Perl/Tk distribution since 800.022).
The following options are new to Tk::LogScale:
- -func
-
Function to translate from real values to internal scale values. By default this is the log function. If you want the 10-log, you can set this option to sub { log($_[0])/log(10) }
- -invfunc
-
This should be the inverse function of -func. By default this is the exp function. For 10-log, use sub { 10**$_[0] }
- -valuefmt
-
Callback to format the value for -showvalue. The default is to show integer values.
ADVERTISED SUBWIDGETS
- scale
-
The scale widget.
- dummy
-
A dummy placeholder for the showvalue area.
- showvalue
-
A label holding the current value of the scale. This one is placed over/left to the thumb of the scale.
BUGS
Multiple ties of the same variable specified in -variable will lead to unpredictable results.
There are still some unimplemented options.
The correct implementation of the -bigincrement, -resolution and -tickinterval options is unclear.
AUTHOR
Slaven Rezic <slaven@rezic.de>