# Problems with IterativeSolvers.svdl() routine

**URL:** <https://discourse.julialang.org/t/problems-with-iterativesolvers-svdl-routine/28866>\
**Category:** New to Julia\
**Created:** [September 17, 2019, 9:17pm UTC](https://discourse.julialang.org/t/problems-with-iterativesolvers-svdl-routine/28866 "2019-09-17T21:17:26Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![iamsuddhasattwa](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/iamsuddhasattwa/32/7441_2.png) [@iamsuddhasattwa](https://discourse.julialang.org/u/iamsuddhasattwa)\
**Post date:** [September 17, 2019, 9:17pm UTC](https://discourse.julialang.org/t/problems-with-iterativesolvers-svdl-routine/28866/1 "2019-09-17T21:17:26Z")

</div>

The svdl() routine of the IterativeSolvers.jl package is giving me completely wrong errors, even for a 4X4 identity matrix. Am I doing something wrong ?

```julia
julia> using IterativeSolvers;

julia> using LinearAlgebra;

julia> K= Diagonal(ones(4));

julia> X,L = IterativeSolvers.svdl(K,nsv=3,vecs=:both);

julia> display(X.S);
3-element Array{Float64,1}:
 8.097516300046776
 6.159726694870877
 5.198283129557383

julia> A=X.U * Diagonal(X.S)*X.Vt
4×4 Array{Float64,2}:
  0.14693 -0.40968 -0.683797 -0.220515
 -0.40968 1.1423 1.90661 0.614855
 -0.683797 1.90661 3.18233 1.02626 
 -0.220515 0.614855 1.02626 0.330953

julia> 

```

As you see, the singular values are all wrong and the factorization does not lead to the original matrix.