...aluenumber giving the maximum of the color values range, see above.
第四个数值，也就是alpha是透明度值 0 完全透明，而最大值意味不透明，简单来说就是控制了颜色的深浅。
譬如最大值255，alpha=20 对应的图片：
barplot(1,1,col=rgb(255,0,0,20,maxColor...
...s -debug_flag io
To see how configuration files work, create the example image, whose
configuration and data are found in example/. From the Circos distribution
directory,
cd example
../bin/circos -conf ./circos.conf
or use the 'run' script (UNIX only).
...