comparing lists

Jan 20, 2012 at 3:45am

comparing lists

Hello all!
Im fairly new to max which im loving so far put i think ive hit my first wall..

I have a list of frequencies that is constantly updating(these are peaks that ive detected with ~fiddle), and Im trying to catch a frequency as it dissapears from the list.

The way I was going to do it was monitor my list and constantly compare the new list as it comes in to the list that came before it.

So Im trying to compare 2 lists of frequencies to see which elements of one list do or do not appear in another, which sounds easy enough, but my frequencies are floats that are always slightly different – I want it to realize that 79.0930 is the same as 81.0028.

How would you go about this?

#61348
Jan 20, 2012 at 4:28am

use one of the zl modes – forget which

#221166
Jan 20, 2012 at 5:02am

Hi Jamesson,
Yeah thats what I thought, i think its called zl compare. But from my understanding it doesnt work if the values it compares arent exactly the same.

I need a threshold setting, for example if my first number is 8.0 i want it to search for anything close to 8.0, not just esactly 8.0

The other thing that zl compare seems to do is only compare the index 1 in list A with the index 1 in list B. I want to compare index 1 in list A with every element of list B.

I could be misunderstanding the way to process things with zl

#221167
Jan 20, 2012 at 6:52am

see under; round

#221168
Jan 20, 2012 at 7:16am

zl sect does the job; in this example I convert the lists into a streams to round the elements to a required accuracy and then convert back to a list to compare; but you could use vexpr to round the elements which would make it more efficient, if you can figure out how to do rounding with it

edit forget about what I said– round processes lists as stated by jamesson, here:

– Pasted Max Patch, click to expand. –
#221169
Jan 20, 2012 at 12:13pm

Wow thanks guys! rounding is the way to go, that example works great.

its so simple I dont know why i was making it so complicated..

#221170

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