Scipy sparse parallel iterative solvers












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I need to solve quite large linear systems (about 1e6 x 1e6, maybe more in future) in python. The matrix is stored in csr format.
I tried scipy.sparse.linalg.spsolve, which is a direct solver and is not applicable due to high RAM consumption.
I had a look at the iterative solvers scipy.sparse.linalg.bicgstab and scipy.sparse.linalg.gmres.
Are these capable of parallel computing? When I use small dimensions, only one core is used, when I use larger dimension (1e6) all 4 cores are used.



Could somebody explain the difference?



Here's a small sample code I use:



import numpy as np
import scipy.sparse as sp
import scipy.sparse.linalg as sp_la

n = int(1e6)

A = sp.spdiags(np.random.rand(3, n), [-1, 0, 1], n, n)
b = np.random.rand(n, 1)

x = sp_la.gmres(A, b)


I want to run the code on a cluster with 48 cpus and right now I am trying the code on my laptop (4 cores).



Thanks










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    0















    I need to solve quite large linear systems (about 1e6 x 1e6, maybe more in future) in python. The matrix is stored in csr format.
    I tried scipy.sparse.linalg.spsolve, which is a direct solver and is not applicable due to high RAM consumption.
    I had a look at the iterative solvers scipy.sparse.linalg.bicgstab and scipy.sparse.linalg.gmres.
    Are these capable of parallel computing? When I use small dimensions, only one core is used, when I use larger dimension (1e6) all 4 cores are used.



    Could somebody explain the difference?



    Here's a small sample code I use:



    import numpy as np
    import scipy.sparse as sp
    import scipy.sparse.linalg as sp_la

    n = int(1e6)

    A = sp.spdiags(np.random.rand(3, n), [-1, 0, 1], n, n)
    b = np.random.rand(n, 1)

    x = sp_la.gmres(A, b)


    I want to run the code on a cluster with 48 cpus and right now I am trying the code on my laptop (4 cores).



    Thanks










    share|improve this question

























      0












      0








      0








      I need to solve quite large linear systems (about 1e6 x 1e6, maybe more in future) in python. The matrix is stored in csr format.
      I tried scipy.sparse.linalg.spsolve, which is a direct solver and is not applicable due to high RAM consumption.
      I had a look at the iterative solvers scipy.sparse.linalg.bicgstab and scipy.sparse.linalg.gmres.
      Are these capable of parallel computing? When I use small dimensions, only one core is used, when I use larger dimension (1e6) all 4 cores are used.



      Could somebody explain the difference?



      Here's a small sample code I use:



      import numpy as np
      import scipy.sparse as sp
      import scipy.sparse.linalg as sp_la

      n = int(1e6)

      A = sp.spdiags(np.random.rand(3, n), [-1, 0, 1], n, n)
      b = np.random.rand(n, 1)

      x = sp_la.gmres(A, b)


      I want to run the code on a cluster with 48 cpus and right now I am trying the code on my laptop (4 cores).



      Thanks










      share|improve this question














      I need to solve quite large linear systems (about 1e6 x 1e6, maybe more in future) in python. The matrix is stored in csr format.
      I tried scipy.sparse.linalg.spsolve, which is a direct solver and is not applicable due to high RAM consumption.
      I had a look at the iterative solvers scipy.sparse.linalg.bicgstab and scipy.sparse.linalg.gmres.
      Are these capable of parallel computing? When I use small dimensions, only one core is used, when I use larger dimension (1e6) all 4 cores are used.



      Could somebody explain the difference?



      Here's a small sample code I use:



      import numpy as np
      import scipy.sparse as sp
      import scipy.sparse.linalg as sp_la

      n = int(1e6)

      A = sp.spdiags(np.random.rand(3, n), [-1, 0, 1], n, n)
      b = np.random.rand(n, 1)

      x = sp_la.gmres(A, b)


      I want to run the code on a cluster with 48 cpus and right now I am trying the code on my laptop (4 cores).



      Thanks







      python parallel-processing scipy iteration solver






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      asked Nov 25 '18 at 15:04









      SebastianSebastian

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