# ODEFunction throwing "ERROR: LoadError: mul\_float: types of a and b must match"
**URL:** https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024
**Category:** Numerics
**Tags:** question, diffeq
**Created:** [May 12, 2021, 1:54pm UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024 "2021-05-12T13:54:18Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@ap2013](https://discourse.julialang.org/u/ap2013)
#### Post date: [May 12, 2021, 1:54pm UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/1 "2021-05-12T13:54:18Z")
What does the following error mean: “ERROR: LoadError: mul\_float: types of a and b must match”?
I am running a code that repeatedly calls a function that creates an ODE problem and solves it. The function is called in a for loop, at each called only one parameter in the ODE changes.
I get the error message most of the time that I run the code. The unusual thing is that the error is raised at different iterations of the for loop, usually after 10 or so successful executions of the function. Sometimes the error is raised at the first or second for loop.
I would appreciate any help understanding what is raising the error and how to fix it.
Please find below the abridged error trace
ERROR: LoadError: mul\_float: types of a and b must match
Stacktrace:
[1] \*
@ ./float.jl:332 [inlined]
[2] macro expansion
@ ~/.julia/packages/SymbolicUtils/9iQGH/src/code.jl:325 [inlined]
[3] macro expansion
@ ~/.julia/packages/Symbolics/Kybuv/src/build\_function.jl:331 [inlined]
[4] macro expansion
@ ~/.julia/packages/SymbolicUtils/9iQGH/src/code.jl:283 [inlined]
[5] macro expansion
@ ~/.julia/packages/RuntimeGeneratedFunctions/3SZ1T/src/RuntimeGeneratedFunctions.jl:124 [inlined]
[6] macro expansion
@ ./none:0 [inlined]
[7] generated\_callfunc
@ ./none:0 [inlined]
[8] (::RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(Symbol(“##out#2420”), Symbol(“##arg#2418”), Symbol(“##arg#2419”), :t), ModelingToolkit.var"#\_RGF\_ModTag", ModelingToolkit.var"#\_RGF\_ModTag", (0x24c64a68, 0xc35b875a, 0x4240b981, 0x23f2fd06, 0xd99ac7f8)})(::Vector{Float64}, ::Vector{Float64}, ::Vector{Float64}, ::Float64)
@ RuntimeGeneratedFunctions ~/.julia/packages/RuntimeGeneratedFunctions/3SZ1T/src/RuntimeGeneratedFunctions.jl:112
[9] f
@ ~/.julia/packages/ModelingToolkit/tBDYj/src/systems/diffeqs/abstractodesystem.jl:168 [inlined]
[10] ODEFunction
@ ~/.julia/packages/SciMLBase/XuLdB/src/scimlfunctions.jl:334 [inlined]
[11] initialize!(integrator::OrdinaryDiffEq.ODEIntegrator{ […]
@ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/vxMSM/src/perform\_step/low\_order\_rk\_perform\_step.jl:623
[12] initialize!(integrator::OrdinaryDiffEq.ODEIntegrator{. […]
@ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/vxMSM/src/perform\_step/composite\_perform\_step.jl:39
[13] \_\_init(prob::ODEProblem{Vector{Float64}, […]
@ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/vxMSM/src/solve.jl:433
[14] \_\_solve(::ODEProblem{Vector{Float64}, Tuple{Float64, Float64}, true, Vector{Float64}, ODEFunction{true, ModelingToolkit.var"#f#148"{RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(Symbol(“##arg#2418”), Symbol(“##arg#2419”), :t), ModelingToolkit.var"#\_RGF\_ModTag", ModelingToolkit.var"#\_RGF\_ModTag", (0x035432df, 0xab964ebf, 0xc3bbf1d1, 0x5aec0fd7, 0x3e286ce7)}, RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(Symbol(“##out#2420”), Symbol(“##arg#2418”), Symbol(“##arg#2419”), :t), ModelingToolkit.var"#\_RGF\_ModTag", ModelingToolkit.var"#\_RGF\_ModTag", (0x24c64a68, 0xc35b875a, 0x4240b981, 0x23f2fd06, 0xd99ac7f8)}}, LinearAlgebra.UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Vector{Symbol}, Symbol, ModelingToolkit.var"#120#generated\_observed#155"{Bool, ODESystem, Dict{Any, Any}}, Nothing}, Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::CompositeAlgorithm{Tuple{Tsit5, TRBDF2{0, true, DefaultLinSolve, NLNewton{Rational{Int64}, Rational{Int64}, Rational{Int64}}, DataType}}, AutoSwitch{Tsit5, TRBDF2{0, true, DefaultLinSolve, NLNewton{Rational{Int64}, Rational{Int64}, Rational{Int64}}, DataType}, Rational{Int64}, Int64}}; kwargs::Base.Iterators.Pairs{Symbol, Vector{Float64}, Tuple{Symbol}, NamedTuple{(:saveat,), Tuple{Vector{Float64}}}})
@ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/vxMSM/src/solve.jl:4
[15] #solve\_call#56
@ ~/.julia/packages/DiffEqBase/U3Zj7/src/solve.jl:61 [inlined]
[16] #solve\_up#58
@ ~/.julia/packages/DiffEqBase/U3Zj7/src/solve.jl:82 [inlined]
[17] #solve#57
@ ~/.julia/packages/DiffEqBase/U3Zj7/src/solve.jl:70 [inlined]
[18] simFFFB(N::Int64, r::Reference{var"#refSin#5"{Vector{Float64}}, StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}}, ref::ODESystem, pid::ODESystem, lp::ODESystem, numIndex::Int64, W0::Matrix{Float64})
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [May 12, 2021, 11:42pm UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/2 "2021-05-12T23:42:25Z")
Can you share your example?
---
### Author:  [@ap2013](https://discourse.julialang.org/u/ap2013)
#### Post date: [May 13, 2021, 7:28am UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/3 "2021-05-13T07:28:49Z")
Hi ChrisRackauckas,
thanks for the response. I don’t really have a minimal example but you can find the whole code here [https://github.com/adrianaprotondo/CerebellumLearning/blob/d6234c1e0324880ac8cdd38be777755f771dc98a/scripts/lossVsSize.jl](https://github.com/adrianaprotondo/CerebellumLearning/blob/d6234c1e0324880ac8cdd38be777755f771dc98a/scripts/lossVsSize.jl)
in this github project directory
[https://github.com/adrianaprotondo/CerebellumLearning.git](https://github.com/adrianaprotondo/CerebellumLearning.git)
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [May 13, 2021, 8:04am UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/4 "2021-05-13T08:04:35Z")
It looks like you’re mixing Float64 and Float32: what if you make that all consistent?
---
### Author:  [@ap2013](https://discourse.julialang.org/u/ap2013)
#### Post date: [May 13, 2021, 8:58am UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/5 "2021-05-13T08:58:09Z")
Thanks for the suggestion! I changed all the Array definition to Float64 and still get the same error. Do you have any other suggestions?
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [May 13, 2021, 12:04pm UTC](https://discourse.julialang.org/t/odefunction-throwing-error-loaderror-mul-float-types-of-a-and-b-must-match/61024/6 "2021-05-13T12:04:38Z")
I can’t say I’ll have time to dig into your example, but maybe @shashi can take a look?