# How do I join two series that have different scales?

A good example of this is combining two series to make one with a longer total history. If these series have different scales, you should use one of the following formulae.

JoinScaled(series1, series2) or JoinScaledAppend(series1, series2)

JoinMoreHistoryScaled(series1, series2)

The difference between these formulae is the order of the series in the expression:

JoinScaled will join ‘series2’ at the end of ‘series1’.

JoinMoreHistoryScaled will add more history to “series1” using the values of “series2” that are before the start of “series1”.

For these formulae, a factor is applied to scale up the series:

JoinScaled: at the date of the junction, “series1” is scaled to be equal to the value of “series2”. The rest of the values of “series1” are then adjusted using the factor used at the date of the junction.

JoinScaledAppend: this works the same way but will scale the second time series instead of the first.

JoinMoreHistoryScaled: at the date of the junction, “series2” is scaled to be equal to the value of “series1”. The rest of the values of “series2” are then adjusted using the factor used at the date of the junction.