Herbie can be used from the command-line or from the browser. This page covers using Herbie from the command line.
The Herbie shell lets you interact with Herbie: you type in input expressions and Herbie prints their more accurate versions. Run the Herbie shell with this command:
herbie shell Herbie 1.4 with seed 2098242187 Find help on https://herbie.uwplse.org/, exit with Ctrl-D herbie>
Herbie prints a seed, which you can use to reproduce a Herbie run, and links you to documentation. Then, it waits for inputs, which you can type directly into your terminal in FPCore format:
herbie> (FPCore (x) (- (+ 1 x) x)) (FPCore (x) ... 1.0)
Herbie suggests that
1 is more accurate than the
(- (+ 1 x) x). The
the ... elides
additional information provided
The Herbie shell makes it easy to play with different expressions and try multiple variants, informed by Herbie's advice.
Alternatively, you can run Herbie on a file with multiple expressions in it, writing Herbie's versions of each to a file. This mode is intended for use by scripts.
herbie improve bench/tutorial.fpcore out.fpcore Starting Herbie on 3 problems (seed: 1809676410)... 1/3 [ 0.769s] 29→ 0 Cancel like terms 2/3 [ 1.392s] 39→ 0 Expanding a square 3/3 [ 2.522s] 0→ 0 Commute and associate
The output file
out.fpcore contains more accurate
versions of each program:
;; seed: 1809676410 (FPCore (x) ... 1.0) (FPCore (x) ... (* x (+ x 2.0))) (FPCore (x y z) ... 0.0)
Note that output file is in the same order as the input file. For more control over Herbie, see the documentation of Herbie's command-line options.