# Hello if you have time can you please look at my code , i am finding this error ArgumentError: invalid index: 0.0 of type Float64 i would really appreciate thanks

**URL:** <https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770>\
**Category:** New to Julia\
**Tags:** question\
**Created:** [January 10, 2023, 7:19pm UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770 "2023-01-10T19:19:31Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![BILEHGUELLEHSAHAL](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bilehguellehsahal/32/43858_2.png) [@BILEHGUELLEHSAHAL](https://discourse.julialang.org/u/BILEHGUELLEHSAHAL)\
**Post date:** [January 10, 2023, 7:19pm UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/1 "2023-01-10T19:19:31Z")

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```julia
using Turing
using DifferentialEquations
using Plots

# Define the differential equation model for the microgrid system
function microgrid_model(dx, x, p, t)
   P_pv, P_wt, P_dg, P_load = x
   A_pv, R_pv, A_wt, R_wt, A_dg, R_dg, A_load, R_load = p
   dx[1] = A_pv * G_t[t] - P_pv / R_pv
   dx[2] = A_wt * wind_speed[t] - P_wt / R_wt
   dx[3] = A_dg - P_dg / R_dg
   dx[4] = A_load - P_load / R_load
end

# Define the prior distributions for the model parameters
A_pv = Normal(5, 2)
R_pv = Gamma(2, 0.5)
A_wt = Normal(5, 2)
R_wt = Gamma(2, 0.5)
A_dg = Normal(5, 2)
R_dg = Gamma(2, 0.5)
A_load = Normal(5, 2)
R_load = Gamma(2, 0.5)

p=[5, 2, 5, 2, 5, 2, 5, 2]
G_t = [0.5, 0.7, 0.9, 1.1, 1.3, 1.5, 1.7, 1.9, 2.1, 2.3] # Solar radiation data in W/m^2
wind_speed = [2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0] # Wind speed data in m/s

# Use the `solve` function from the DifferentialEquations.jl package to solve the differential equations
# and get the solution at each point in time
tspan = (0.0, 10.0)
x0 = [1.0, 2.0, 3.0, 4.0]
prob = ODEProblem(microgrid_model, x0, tspan, p)
sol = solve(prob, Tsit5())

# Generate some synthetic data from the solution of the differential equation model
data = [sol(t) + randn() * 0.1 for t in tspan[1]:0.1:tspan[2]]

# Perform inference
microgrid_trace = sample(microgrid_model, data, HMC(1000, 0.1), p)
```

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**Author:** ![Krastanov](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/krastanov/32/6817_2.png) [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Post date:** [January 10, 2023, 7:42pm UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/2 "2023-01-10T19:42:10Z")

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You will certainly get help from multiple users shortly 🙂 But just to help everyone, it would be easier to read your code if you format it as code by using ``` backquotes. [Please read: make it easier to help you](https://discourse.julialang.org/t/please-read-make-it-easier-to-help-you/14757)

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**Author:** ![Paul\_Schrimpf](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/paul_schrimpf/32/10134_2.png) [@Paul\_Schrimpf](https://discourse.julialang.org/u/Paul_Schrimpf)\
**Post date:** [January 10, 2023, 7:42pm UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/3 "2023-01-10T19:42:33Z")

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In your `microgrid_model` function, you have `G_t[t]` and `windspeed[t]`. Indexing expects `t` to be an `Int`, but inside `solve`, `t` is a `Float64`.

I don’t know what the intention of the code is, maybe you want something like `G_t[Int(ceil(t))]`. More likely, you want something such as

```julia
using Interpolations
Ginterp = linear_interpolation(ts, G_t,extrapolation_bc=Line()) 

# then inside microgrid_model replace G_t[t] with Ginterp(t)

```

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**Author:** ![vettert](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vettert/32/30599_2.png) [@vettert](https://discourse.julialang.org/u/vettert)\
**Post date:** [January 10, 2023, 7:43pm UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/4 "2023-01-10T19:43:02Z")

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You cannot index arrays with a floating point number; in your code you do it twice: wind\_speed[t] and G\_t[t]

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**Author:** ![BILEHGUELLEHSAHAL](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bilehguellehsahal/32/43858_2.png) [@BILEHGUELLEHSAHAL](https://discourse.julialang.org/u/BILEHGUELLEHSAHAL)\
**Post date:** [January 11, 2023, 11:12am UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/6 "2023-01-11T11:12:21Z")

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i will try thanks

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<div class="post-metadata">

**Author:** ![BILEHGUELLEHSAHAL](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bilehguellehsahal/32/43858_2.png) [@BILEHGUELLEHSAHAL](https://discourse.julialang.org/u/BILEHGUELLEHSAHAL)\
**Post date:** [January 11, 2023, 11:13am UTC](https://discourse.julialang.org/t/hello-if-you-have-time-can-you-please-look-at-my-code-i-am-finding-this-error-argumenterror-invalid-index-0-0-of-type-float64-i-would-really-appreciate-thanks/92770/7 "2023-01-11T11:13:11Z")

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yes i see you are right thanks