In the 'help' tab of the
ui-gauge there is a link 'Angular filters' that previously took you to a website with a tutorial
all about the built in angularjs filters but the website no longer exists and you are taken to
A PR has been created to change the link to point to
You can always do a google search using
all about the built in angularjs filters to find other sites with explainations of how to use the Angular filters.