Scipy sparse parallel iterative solvers












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















    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






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 25 '18 at 15:04









      SebastianSebastian

      11




      11
























          0






          active

          oldest

          votes











          Your Answer






          StackExchange.ifUsing("editor", function () {
          StackExchange.using("externalEditor", function () {
          StackExchange.using("snippets", function () {
          StackExchange.snippets.init();
          });
          });
          }, "code-snippets");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "1"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53468798%2fscipy-sparse-parallel-iterative-solvers%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Stack Overflow!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53468798%2fscipy-sparse-parallel-iterative-solvers%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          404 Error Contact Form 7 ajax form submitting

          How to know if a Active Directory user can login interactively

          TypeError: fit_transform() missing 1 required positional argument: 'X'