Hi, After updating graph-tool ( to version |2.2.31 (commit 245d1e2c, Thu Mar 27 11:28:39 2014 +0100)|), and a bunch of over things as I passed to Mint 15 to Mint 16, I encounter the following value error, when I manipulates parts of a PropertyMap (through indexing or via the |.fa| attribute (bellow, |dthetas| is an edge propertymap on a graph): |lower_than = [dthetas.a < -tau/2.] dthetas.a[lower_than] += tau ValueError: output arrayis read-only| Note that the following doesn't rise the error: | lower_than = [dthetas.a < -tau/2.] dthetas.a[lower_than] = dthetas.a[lower_than] + tau| It also happen when I filter a graph and do for example |eprop.fa *= 2| I just wanted to know if this is expected, and I‘ll go fix my code everywhere I do that kind of assignation, or if it is unintended (and I’ll go fix my code anyway ;-). Best, Guillaume