PDL::Char(3pm)

💖 PDL::Char — the perl manual page, but make it cute 💖

ok so bestie, lemme tell you about PDL::Char, which is a PDL subclass that lets you read and write fixed-length character strings as byte PDLs. it's giving "strings but make it arrays" and honestly it ate. this is part of User Contributed Perl Documentation, iykyk 💅

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✨ SYNOPSIS ✨

use PDL;
use PDL::Char;

my $pchar = PDL::Char->new( [['abc', 'def', 'ghi'],['jkl', 'mno', 'pqr']] );

$pchar->setstr(1,0,'foo');

print $pchar; # 'string' bound to "", perl stringify function
# Prints:
# [
#  ['abc' 'foo' 'ghi']
#  ['jkl' 'mno' 'pqr']
# ]

print $pchar->atstr(2,0);
# Prints:
# ghi

---

🌸 DESCRIPTION 🌸

so basically this subclass of PDL lets you manipulate PDLs of 'byte' type as if they were made of fixed length strings, not just numbers. no cap, that's the whole vibe 🦋

this kind of behavior is highkey useful when you wanna work with character grids. and here's the important part bestie: the indexing is done on a string level and not a character level for the 'setstr' and 'atstr' commands. periodt.

this module is in particular useful for writing NetCDF files that include character data using the PDL::NetCDF module. obsessed 🎀

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🔥 FUNCTIONS 🔥

🌈 new

function to create a byte PDL from a string, list of strings, list of list of strings, etc. she's flexible, she's iconic 👑

# create a new PDL::Char from a perl array of strings
$strpdl = PDL::Char->new( ['abc', 'def', 'ghij'] );

# Convert a PDL of type 'byte' to a PDL::Char
$strpdl1 = PDL::Char->new (sequence (byte, 4, 5)+99);

$pdlchar3d = PDL::Char->new([['abc','def','ghi'],['jkl', 'mno', 'pqr']]);

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🦋 string

function to print a character PDL (created by 'char') in a pretty format. she's the main character of formatting, fr fr ✨

$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
#  ['abc' 'def' 'ghi']
#  ['jkl' 'mno' 'pqr']
# ]

# 'string' is overloaded to the "" operator, so:
# print $char;
# should have the same effect.

---

💅 setstr

function to set one string value in a character PDL. the input position is the position of the string, not a character in the string. the first dimension is assumed to be the length of the string. okay so keep up 👀

the input string will be null-padded if the string is shorter than the first dimension of the PDL. it will be truncated if it is longer. no drama, she just does it.

$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
$char->setstr(0,1, 'foobar');
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
#  ['abc' 'def' 'ghi']
#  ['foo' 'mno' 'pqr']
# ]
$char->setstr(2,1, 'f');
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
#  ['abc' 'def' 'ghi']
#  ['foo' 'mno' 'f']      -> note that this 'f' is stored "f\0\0"
# ]

---

🍓 atstr

function to fetch one string value from a PDL::Char type PDL, given a position within the PDL. the input position is the position of the string, not a character in the string. the length of the input string is the implied first dimension. she's setstr's ✨glow-up sibling✨ 💜

$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
print $char->atstr(0,1);
# Prints:
# jkl

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🫶 quick reminder bestie: the input position for both setstr and atstr is a string index, not a character index. literal character-level indexing is not what's happening here, and that's on purpose. slay.

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💖 the cute lil sign-off 💖

this page is perl v5.42.3, dated 2026-08-20, and it's the PDL::Char(3pm) manual — go forth and manipulate your fixed-length strings with main character energy, bestie, you got this 🌟💅🧚💜