Hello �
The octave spectrum coming from the 1/3 octave analysis vi is a cluster of 2 elements.
Normally you would use a build array function to create a multiplot graph. However, all the plots going into the build array function have to have the same data type. A cluster of 2 elements and a cluster of 3 elements is not the same data type.
You need to express your narrowband data in a 2 element cluster to be able to plot it in the same octave graph.
Hope this helps.
S Vences
National Instruments