The currency strength indicator takes up to 4 forex pairs and calculates the average strength across all pairs. The indicator uses the pair's daily percentage change to calculate the overall strength. For flexibility, it can accept any instrument as an input. This means you can use multiple instances to track various currency strengths. It was designed with the major pairs in mind but there is no reason why it cannot be used for other FX pairs.
Note: The indicator defaults to GBP. When setting it up for other currencies, be sure to flag whether the currency is a counter currency or not.
The code is provided free and open source. Please modify it as you see fit.
Defaults with Annotation
Yen strength beating pound strength
Fix for NA values that recently started to appear.