isnan(3)

🌸 isnan(3) — the "is this even a number" vibe check 💅

ok so bestie, real talk: this page lives in the Library Functions Manual and it's all about one iconic little question — is this thing NaN or not? Two functions do the exact same job, just for two different flavours of float. Slay. ✨

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✨ SYNOPSIS ✨

Like, here's the whole cast 🎀:

logical function DISNAN (din)
    DISNAN tests input for NaN.
logical function SISNAN (sin)
    SISNAN tests input for NaN.

That's it. That's the roster. Two little icons, one job. 👑

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💖 Detailed Description 💖

ngl, there's not much here — this is the "detailed description" section and it's basically showing up to the group chat with nothing to say. The real tea is in the function docs down below. Scroll with me. 🫶

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🦋 Function Documentation 🦋

🍓 logical function DISNAN (double precision, intent(in) din)

DISNAN tests input for NaN. That's the whole assignment, and it ate. 💅

Purpose:

!> !> DISNAN returns .TRUE. if its argument is NaN, and .FALSE. !> otherwise. To be replaced by the Fortran 2003 intrinsic in the !> future. !>

So like — yes = NaN, no = not NaN, extremely straightforward. But the manpage is literally telling you this one is on its way out and will be replaced by the Fortran 2003 intrinsic in the future. Not deprecated-deprecated, but it's giving "legacy era", iykyk. 🙈

Parameters

• DIN — lowkey the only thing you pass in here:

!> DIN is DOUBLE PRECISION !> Input to test for NaN. !>

So it's a DOUBLE PRECISION value, and it's the input to test for NaN. That's it, babes. No tricks, no secret flags. 🌈

Author

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Four whole institutions on the credits. main character energy fr fr. 👑

Definition at line 58 of file disnan.f.

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🧚 logical function SISNAN (real, intent(in) sin)

SISNAN tests input for NaN. Same vibe check, single-precision edition. ⭐

Purpose:

!> !> SISNAN returns .TRUE. if its argument is NaN, and .FALSE. !> otherwise. To be replaced by the Fortran 2003 intrinsic in the !> future. !>

Literally the identical promise as its sibling: .TRUE. when it's NaN, .FALSE. when it's not, and heads up — it's going to be replaced by the Fortran 2003 intrinsic in the future. So like, use it, love it, but know the era is ending. 😭

Parameters

• SIN — the one and only input:

!> SIN is REAL !> Input to test for NaN. !>

A REAL value, and it's the input to test for NaN. Periodt. 💜

Author

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Same legendary squad, same credit list. 🫶

Definition at line 58 of file sisnan.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

Bestie, nobody hand-wrote this — Doxygen did it for LAPACK straight from the source. A robot wrote our homework and honestly? It understood the assignment. 💀✨

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ok that's the whole page, no cap — every flag, file, line number and credit is in here, nothing skipped, nothing invented. mwah 💋

— LAPACK, Version 3.12.0, signing off 🎀