import Statistics.Sample import Statistics.Distribution.Normal main :: IO () main = do let sample = [1.0, 2.0, 3.0, 4.0, 5.0] print $ mean sample print $ stdDev sample
3.0 1.5811388300841898 Congratulations – you have successfully “downloaded” and installed Gtools via Cabal. Error 1: cabal: Package not found – gtools Cause: There is no official gtools package on Hackage. Fix: Use cabal install statistics or cabal install hstats . Error 2: Missing dependencies: base <4.14 Cause: Your GHC version is too old or too new. Fix: Use GHCup to switch to a compatible GHC version (e.g., GHC 9.0 or 9.2).
curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh Follow the interactive prompts. This installs ghc , cabal , and stack . cabal --version You should see something like: cabal-install version 3.10.1.0 Step 3: Update Your Package List cabal update This downloads the latest package index from Hackage. The Actual Gtools Cabal Download Now that the toolchain is ready, you have two options depending on your intent. Option A: Download the Source (Without Installing) If you want to inspect the code or manually compile later: gtools cabal download
For 95% of users, cabal install is what they need. But because you searched for “download,” we will cover both. Prerequisites You cannot run cabal download without Haskell’s toolchain. Follow these steps first. Step 1: Install GHC (Glasgow Haskell Compiler) and Cabal The best way is to use GHCup – the universal Haskell installer.
Open your terminal (Command Prompt, PowerShell, Terminal.app, or bash) and run: import Statistics
cabal init my-stats-project cd my-stats-project cabal add statistics cabal build Cause: Firewall or corporate proxy blocking Hackage. Fix: Configure Cabal to use a mirror or set HTTP instead of HTTPS:
rm -rf ~/.cabal/lib/x86_64-linux-ghc-9.2.8/statistics-* Yes. After cabal install statistics --lib , launch IHaskell and run: Error 2: Missing dependencies: base <4
If you are absolutely certain there is a legacy package named gtools on Hackage (there isn’t as of 2025), you would run: