Gradient expression not working or obsolete?

[Joolsey1973]

There used to be a neat exprssion that could scale an object, however it seems to be not working as desired when I returned to this effect. Tutorial here:  https://www.youtube.com/watch?v=1UaZNcVobhg

So the that if you get a array of object you get this nice wave effect. 

When trying this there appears to be no scale, rather just 0 or 100, but nothing in the middle. 

I was wondering if it was the scripting preferences Java/legacy extented but both are not working. 

Also I am in 32bit and also 8bit.  I am no great expression user, but this has normally worked straight away in the past. 

I thought at first it might be the vector files but it also is the same with native vectors 'shape layers' from after effects. 

And no recognition of the gradient driving the scale. 

x = thisComp.layer("Gradient").sampleImage(transform.position, [.5,.5]/2, true, time)[0];

100*[x,x]

Best regards Julian

[Joolsey1973 · Accepted solution]

Ok I fixed it. I because the comp had alpha instead of black.  Silly user error.