D2-C(1)

💅 d2-c — the BRL-CAD girlie's guide 💅

okay so bestie, welcome to d2-c, straight out of the BRL-CAD family ✨ this one's a tiny little icon and it has exactly one job. let's get into it 🫶

---

🌸 NAME 🌸

d2-c — merges two double files into one single complex file. that's it. that's the whole personality 💅

---

🎀 SYNOPSIS 🎀

d2-c _real_file_ _imag_file_ > _complex_

---

✨ DESCRIPTION ✨

okay so here's the vibe: d2-c interleaves two separate streams of double-precision floating point values into one single stream of complex numbers, and writes the whole thing out to standard output. it reads values in parallel from real_file and imag_file and emits them as alternating real/imaginary pairs. so the output is literally built to be fed into tools that expect complex data — like dfft(1) 👑

and if one input is shorter than the other? no stress 💖 the missing values get padded with zeros until both inputs are exhausted. everything comes out even, nobody gets left behind.

⚠️ heads up: the output is binary, so you must redirect standard output to a file or a pipe. the program literally refuses to run when standard output is a terminal 😤 no cap.

fun fact: d2-c is the inverse of c-d(1). they're giving matching-friends energy 🦋

either input name can be special, and both tricks are lowkey iconic:

• a single dash (-) — reads that input from standard input
• a single period (.) — supplies an all-zero (null) stream, which is super useful for building a purely real or purely imaginary complex signal 🌈

💀 one sad thing: this command is deprecated and scheduled for removal. so if you depend on it, please contact the developers. don't say i didn't warn you 🙈

---

🌟 EXAMPLES 🌟

💖 Example 1. Build a complex signal from separate real and imaginary files

d2-c real.d imag.d > signal.c

reads matching real and imaginary sample streams and writes the interleaved complex result to signal.c — all ready for spectral analysis with dfft(1) ⭐

🦋 Example 2. Promote a purely real signal to complex form

d2-c real.d . > signal.c

pairs each real sample with a zero imaginary part by using the . null stream, producing a complex file with no imaginary component. genuinely so clean ✨

---

👑 SEE ALSO 👑

brlcad(1), c-d(1), dconv(1), dfft(1)

---

🍓 AUTHOR 🍓

BRL-CAD Team — kings, honestly 🫶

---

💜 COPYRIGHT 💜

This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.

---

🧚 BUG REPORTS 🧚

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org — they genuinely wanna hear from you, bestie 💌

---

okay that's the whole page!! ✨ this little darling comes to you from BRL-CAD (that's the source/version, mwah 💋) and yeah, that's the entire manual. go interleave some doubles, you main character 🎀💅