I hvave no idea what wrong . Please help! julia> for i=1:length(przedzaly)-1 var_name=Symbol("lista_polaczona_" * string(litery[i])) println(var_name) @eval $var_name=lista[przedzaly[i]+1:przedzaly[i+1],:] @eval writedlm("listy_wysylkowe/$var_name.csv",$var_name) …

Please see: [image] PSA: how to quote code with backticks Meta Discussion This is a short post on how to use backticks (` and ```) to quote code, so it is easy to read. This post can be linked to new users who are confused by this feature. Why By quoting your…

Word of advice: never ever use @eval in calculations. If you think that it is impossible to make calculations without @eval it means that your mental model of how Julia works is wrong. There are very good tutorials and docs online, which can give a proper understanding of good Julia code.

In particular, @eval evaluates in global scope, while i is local to your for loop, an MWE would be: julia> for i = 1:10 var_name = Symbol("list", i) @eval $var_name = rand(10)[i] end ERROR: UndefVarError: i not defined that said I don’t see why you’re using @eval here …

You can interpolate variables with $ within @eval expressions. With the MWE above: julia> for i = 1:10 var_name = Symbol("list", i) @eval $var_name = rand(10)[$i] end julia> list1 0.2126448445398994

Yes thanks, but now is Error like below, but without while "for "code is working when I declare “i” . julia> for i=1:length(przedzaly)-1 var_name=Symbol("lista_polaczona_" * string(litery[i])) println(var_name) @eval $var_name=lista[przedzaly[$i]+1:przedzaly[$i+1],:] @ev…

Could you explain what are you trying to do with eval? It seems that you are trying to generate a variable name programatically but in your example this is not necessary and probably in your program it also isn’t. Are you trying to port a code from maltab? Why not something like this? julia> for i…

I have no idea what's wrong. Please help! ERROR: UndefVarError: i not defined

General Usage

kristoffer.carlsson July 28, 2021, 6:54am 2

Please see:

and

Topic		Replies	Views
@eval in loop error General Usage	3	1186	October 4, 2018
Why isn't `i` defined inside this while? Optimization (Mathematical) question	4	533	September 1, 2020
`eval(Symbol("varname")` causes `UndefVarError` although the variable is defined General Usage	8	672	March 20, 2024
Help me with @eval General Usage question	5	432	April 15, 2021
Scope of variables New to Julia scope	3	412	October 19, 2022

I have no idea what's wrong. Please help! ERROR: UndefVarError: i not defined

Related topics