I try to make a patch that includes the object ln~ but when I try to place it I'm getting this:
any idea why ?

Thanks!

There's no such object pd vanilla. Don't know about extended or purr data. If you're trying to do natural logarithm you can do that with [expr~].Or [line~] might be the one you are looking for?

I tried to imitate that patch from the book by Andy Farnell

there is in the middle of the patch an object called ln~

Natural Logarithm it is. Either he used an abstraction of his own, or an object of his own, or an extended object. It exists in Purr Data (I just checked), so the easiest solution might be to install that one besides your pd vanilla installation (I'm running both on linux)

@bocanegra said:

Purr Data

Thanks! I download the purr Data and could make the ln~ object.

@omer1789 Pd solution:

1. Web search "pure data ln"
2. Click first result
3. Search "ln" on page brings you to "ln~ - flatspace motex - log~"
4. In Pd go to Help -> Find externals
5. Type in "motex" and install the top most result
6. Restart Pd
7. [ln~] works