[BUG] nan_triangle returns full triangle when is_pattern

[henrydingliu]

Are you on the latest chainladder version?

• Yes, this bug occurs on the latest version.

Describe the bug in words

Working on converting some xp.ones to nan_triangle. came across this logic. not sure why a full nan_triangle would be needed for ATA factors.

will leave this open for a week or so in case anyone recalls the original intent

How can the bug be reproduced?

raa = cl.load_sample("raa")
raa.age_to_age.nan_triangle

What is the expected behavior?

[[ 1.  1.  1.  1.  1.  1.  1.  1.  1.]
 [ 1.  1.  1.  1.  1.  1.  1.  1. nan]
 [ 1.  1.  1.  1.  1.  1.  1. nan nan]
 [ 1.  1.  1.  1.  1.  1. nan nan nan]
 [ 1.  1.  1.  1.  1. nan nan nan nan]
 [ 1.  1.  1.  1. nan nan nan nan nan]
 [ 1.  1.  1. nan nan nan nan nan nan]
 [ 1.  1. nan nan nan nan nan nan nan]
 [ 1. nan nan nan nan nan nan nan nan]]

Would you be willing to contribute this ticket?

• Yes, absolutely!
• Yes, but I would like some help.
• No.