How to plot double y axis when data sets are from different files?

I have two data sets in two different files as attached. In test1 i want to plot column 1 as x-axis (which is altitude) with column 2 and 3 as y1 axis with different legends. In the same figure I want to plot column 1 as x-axis (which is also altitude but the scale division is different) with column 5 as y2 axis.

[KSSV]

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Answer 1

[madhan ravi]

1)load two text files and assign the values to separate variables.

2) Use yy axis left and yy axis right to plot them.