true/false items into list

hey.

i want to to get the center of circles that are bigger than a certain value. i evaluate the numbers with the "larger than" box, which gives me true/false for each item. now i just want to write the numbers which are true into a list. so if anyone's got a solution/link... 

i found a thread dealing with this, but i failed to reproduce the result.

"workflow which will generate such a parallel data tree of indices consists of 4 components. first of all, take a "list length" component and connect it to your datatree. then use series (connect list length to C input) to generate all indices. next step is to cull indices which are not true (or false). you should use "equality" component and provide as A your primary datatree, as B one value (true or false). last step is to cull indices with pattern obtained with equality, use "cull pattern" to achieve that (data tree from series as list, pattern taken from equality)."

thanks in advance,

matt