# Variable start values from Dict
**URL:** https://discourse.julialang.org/t/variable-start-values-from-dict/124650
**Category:** Optimization (Mathematical)
**Created:** [January 10, 2025, 5:27pm UTC](https://discourse.julialang.org/t/variable-start-values-from-dict/124650 "2025-01-10T17:27:32Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@maxminn](https://discourse.julialang.org/u/maxminn)
#### Post date: [January 10, 2025, 5:27pm UTC](https://discourse.julialang.org/t/variable-start-values-from-dict/124650/1 "2025-01-10T17:27:32Z")
I want to initialize a variable that is indexed by sets of strings to a dictionary with keys that are tuples of those same sets
```Julia
A = ["cat","dog"]
R = ["E" , "W"]
X0 = Dict(
("cat","E") => 1.1,
("cat","W") => 1.2,
("dog","E") => 1.3,
("dog","W") => 1.4
)
m1 = Model()
@variable(m1, X[A,R], start = X0)
```
Gives: ERROR: Unable to use `Dict...` as the start value of a variable because it is not convertable to type `::Float64`.
If I convert to an array …
```Julia
nA = length(A)
nR = length(R)
X00 = zeros(2,2)
for i in 1:nA
for j in 1:nR
X00[i,j] = X0[A[i],R[j]]
end
end
@variable(m1, X[A,R], start = X00)
@variable(m1, X[A,R], start = X00[i,j] for i in 1:nA for j in 1:nR)
```
Gives: ERROR: Passing arrays as variable starts without indexing them is not supported.
And : ERROR: Unrecognized positional arguments…
respectively.
Any thoughts on the best way to do this?
---
### Author:  [@maxminn](https://discourse.julialang.org/u/maxminn)
#### Post date: [January 10, 2025, 7:27pm UTC](https://discourse.julialang.org/t/variable-start-values-from-dict/124650/2 "2025-01-10T19:27:40Z")
Ok, I figured this out. You can use the Dict directly. Here’s what worked:
```Julia
A = ["cat","dog"]
R = ["E" , "W"]
X0 = Dict(
("cat","E") => 1.1,
("cat","W") => 1.2,
("dog","E") => 1.3,
("dog","W") => 1.4
)
m1 = Model()
@variable(m1, X[i = A,j = R], start = X0[i,j])
```
Thank you for the interest.
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [January 10, 2025, 7:31pm UTC](https://discourse.julialang.org/t/variable-start-values-from-dict/124650/3 "2025-01-10T19:31:07Z")
You beat me to replying 😄 Yes, using indices is the correct way to solve this problem.