# Confusing/misleading error message for a beginner

**URL:** <https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277>\
**Category:** New to Julia\
**Tags:** dataframes, error-message, dataframesmeta\
**Created:** [December 5, 2022, 8:52pm UTC](https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277 "2022-12-05T20:52:52Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![Ruffus\_Goodman](https://avatars.discourse-cdn.com/v4/letter/r/dbc845/32.png) [@Ruffus\_Goodman](https://discourse.julialang.org/u/Ruffus_Goodman)\
**Post date:** [December 13, 2022, 3:42am UTC](https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277/11 "2022-12-13T03:42:48Z")

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Guys, newbie here.

Lesson “Factorizations” from “Introduction to Julia (for programmers)” course teaches you about lu(matrix) function. Then I got this message:

> julia\> A = randn(3,3)  
> 3×3 Matrix{Float64}:  
> 0.755352 -1.38128 0.0734177  
> 0.507111 2.30187 1.01948  
> -0.833079 1.09402 -2.687
> 
> julia\> l,u,p = lu(A)  
> ERROR: UndefVarError: lu not defined  
> Stacktrace:  
> [1] top-level scope  
> @ REPL[188]:1

`> Blockquote`

The lesson didn’t mention you’re now using a LinearAlgebra package function. I just wanted to add this somewhere as I couldn’t find a topic related to this course. This might be obvious, but I needed to look up on the internet to proceed.

Anyway, I hope this helps

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_[View the full topic](https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277)._