Only preallocated one vector for preconditioners #187
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| @@ -4,7 +4,7 @@ using LinearAlgebra | |||
| function wrap_preconditioners(kwargs) | |||
| if (haskey(kwargs, :M) && typeof(kwargs[:M]) <: AbstractMatrix) || (haskey(kwargs, :N) && typeof(kwargs[:N]) <: AbstractMatrix) | |||
| k = keys(kwargs) | |||
| v = Tuple(typeof(arg) <: AbstractMatrix ? PreallocatedLinearOperator(arg) : arg for arg in values(kwargs)) | |||
| v = Tuple(typeof(arg) <: AbstractMatrix ? PreallocatedLinearOperator(arg, symmetric=true) : arg for arg in values(kwargs)) | |||
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With GMRES & co., preconditioners could be non-symmetric.
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Yes, but we only need M⁻¹ * v products. I did the same thing with A for CGS, DIOM and DQGMRES even if A is not symmetric.
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I see. It's worth adding a comment around your last change to explain that.
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With the option symmetric=true, we preallocate matrix-vector products with A and A' with the same vector. If we don't use / need products with A' it's the good thing to do even if A is not symmetric.
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| @@ -4,6 +4,7 @@ using LinearAlgebra | |||
| function wrap_preconditioners(kwargs) | |||
| if (haskey(kwargs, :M) && typeof(kwargs[:M]) <: AbstractMatrix) || (haskey(kwargs, :N) && typeof(kwargs[:N]) <: AbstractMatrix) | |||
| k = keys(kwargs) | |||
| # Matrix-vector products with Mᵀ and Nᵀ are not required, we can safely use one vector for products with M / Mᵀ and N / Nᵀ | |||
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Please explain that that's why you set symmetric=true somewhere. Otherwise, I'm sure we'll forget and puzzle over this in 6 months time.
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Thank you. |
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