# Problem Float32 sparse matrix solver

**URL:** <https://discourse.julialang.org/t/problem-float32-sparse-matrix-solver/19812>\
**Category:** General Usage\
**Created:** [January 19, 2019, 12:03pm UTC](https://discourse.julialang.org/t/problem-float32-sparse-matrix-solver/19812 "2019-01-19T12:03:12Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![LaurentPlagne](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/laurentplagne/32/10103_2.png) [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Post date:** [January 19, 2019, 12:03pm UTC](https://discourse.julialang.org/t/problem-float32-sparse-matrix-solver/19812/1 "2019-01-19T12:03:12Z")

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Hi,  
The following code fails (`MethodError: no method matching lu!(::SparseMatrixCSC{Float32,Int64}, ::Val{true}; check=true)`) with julia 1.0.3.

```julia
using SparseArrays
const MyFloat=Float32

n=40
d3=zeros(MyFloat,(n,n))
for i=1:n
    d3[i,i]=MyFloat(-4)
    if i>1 d3[i,i-1]=MyFloat(1) end
    if i<n d3[i,i+1]=MyFloat(1) end
end

sp3=sparse(d3)
b=[MyFloat(i) for i=1:40]
x=zeros(MyFloat,40)
x=sp3\b

```

Note that it is OK if I use `MyFloat=Float64`.

Any hints ?

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<div class="post-metadata">

**Author:** ![mohamed82008](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mohamed82008/32/18171_2.png) [@mohamed82008](https://discourse.julialang.org/u/mohamed82008)\
**Post date:** [January 19, 2019, 12:19pm UTC](https://discourse.julialang.org/t/problem-float32-sparse-matrix-solver/19812/2 "2019-01-19T12:19:53Z")

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Similar to [https://github.com/JuliaLang/julia/issues/25986](https://github.com/JuliaLang/julia/issues/25986).

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<div class="post-metadata">

**Author:** ![LaurentPlagne](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/laurentplagne/32/10103_2.png) [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Post date:** [January 19, 2019, 12:29pm UTC](https://discourse.julialang.org/t/problem-float32-sparse-matrix-solver/19812/3 "2019-01-19T12:29:53Z")

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Thanks,  
reading the issue comments, there is no clear hint indicating if it will be corrected… The error message could be a bit more explicit: would have save me a little time 😉