# Help me with repeated index
**URL:** https://discourse.julialang.org/t/help-me-with-repeated-index/35339
**Category:** Optimization (Mathematical)
**Created:** [February 29, 2020, 8:53pm UTC](https://discourse.julialang.org/t/help-me-with-repeated-index/35339 "2020-02-29T20:53:04Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@varun\_yaramasu](https://discourse.julialang.org/u/varun_yaramasu)
#### Post date: [February 29, 2020, 8:53pm UTC](https://discourse.julialang.org/t/help-me-with-repeated-index/35339/1 "2020-02-29T20:53:04Z")
```julia
using JuMP,SCS
m=Model(with_optimizer(SCS.Optimizer))
branch=[1 2 0.1
3 4 0.1
4 5 0.2
4 6 0.3
5 6 0.1
]
```
If we want only the first column of the branch, what we have to do ?
I mean , if I write like this this
```julia
S=[(branch[r,1]) for r= 1:size(branch,1)]
@variable(m,v[S])
```
I’m getting the error.
Like this
```julia
ERROR: LoadError: Repeated index 4.0. Index sets must have unique elements.
```
Please help me
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [February 29, 2020, 9:49pm UTC](https://discourse.julialang.org/t/help-me-with-repeated-index/35339/2 "2020-02-29T21:49:27Z")
You cannot create a JuMP variable with duplicate indices. See, e.g.,
```nohighlight
model = Model()
@variable(model, x[[:a, :a, :b]])
x[:a] # Which `:a` is this referring to?
```
As [I said in the other post](https://discourse.julialang.org/t/help-me-with-indexing/35203/2), you probably intend
```nohighlight
model = Model()
@variable(model, v[1:size(branch, 1)])
v[3] # Corresponds to (4, 5, 0.2)
```
p.s. Please don’t open multiple posts with the same question: [Help me with indexing - #4 by varun\_yaramasu](https://discourse.julialang.org/t/help-me-with-indexing/35203/4). It can lead to the answers being split over multiple posts.