vector a
Array
(
    [0] => 2
    [1] => 3
    [2] => foo
    [3] => 5.5
    [4] => 43.3
    [5] => 21.11
)
----
vector b - a notice (b = log(PI) * a)
<b>My NOTICE</b> [1024] Value at position 2 is not a number, using 0 (zero)<br />
Array
(
    [0] => 2.2894597717
    [1] => 3.43418965755
    [2] => 0
    [3] => 6.29601437217
    [4] => 49.5668040573
    [5] => 24.1652478903
)
----
vector c - a warning
<b>My WARNING</b> [512] Incorrect input vector, array of values expected<br />
NULL
----
vector d - fatal error
<b>My ERROR</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br />
  Fatal error on line 40 in file /home/admin5086/public_html/responsive/bh/zzzindex.php, PHP 5.5.38 (Linux)<br />
Aborting...<br />