$vectorRef = { 'time' => \(), 'data' => \() };
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This doesn't do what you think it does. \() create a list of references to things inside the parens, making it an empty list. So, you create a reference to a hash containing just one key/value pair, 'time' being the key, 'data' being the value.

What you want is:

$vectorRef = {time => [], data => []};
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Or perhaps just

$vectorRef = {};
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as Perl will happily autovivify the arrays for you.

Abigail