{"title":"求解大型非对称线性系统的改进CMRH方法","authors":"Qianqian Xue, Wenli Zeng, Xiaoqi Xu, Xian-Ming Gu","doi":"10.1016/j.aml.2025.109672","DOIUrl":null,"url":null,"abstract":"<div><div>This paper presents a modified CMRH method for solving large nonsymmetric linear systems. Based on the Hessenberg process, the proposed method requires less computation and storage compared to GMRES and QMR methods. The improvement involves utilizing the <span><math><mrow><mo>(</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-th vector generated during the Hessenberg process to optimize the approximate solution through a linear combination, thereby reducing the number of matrix–vector multiplications and inner products. Theoretical analysis demonstrates that the improved CMRH method is more cost-effective than the original <span><math><mrow><mo>(</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-step method. Numerical experiments validate the efficiency of the modified CMRH method across various test problems, showing fewer iterations and less computation time, particularly in large-scale problems.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":"171 ","pages":"Article 109672"},"PeriodicalIF":2.8000,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A modified CMRH method for solving large nonsymmetric linear systems\",\"authors\":\"Qianqian Xue, Wenli Zeng, Xiaoqi Xu, Xian-Ming Gu\",\"doi\":\"10.1016/j.aml.2025.109672\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This paper presents a modified CMRH method for solving large nonsymmetric linear systems. Based on the Hessenberg process, the proposed method requires less computation and storage compared to GMRES and QMR methods. The improvement involves utilizing the <span><math><mrow><mo>(</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-th vector generated during the Hessenberg process to optimize the approximate solution through a linear combination, thereby reducing the number of matrix–vector multiplications and inner products. Theoretical analysis demonstrates that the improved CMRH method is more cost-effective than the original <span><math><mrow><mo>(</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-step method. Numerical experiments validate the efficiency of the modified CMRH method across various test problems, showing fewer iterations and less computation time, particularly in large-scale problems.</div></div>\",\"PeriodicalId\":55497,\"journal\":{\"name\":\"Applied Mathematics Letters\",\"volume\":\"171 \",\"pages\":\"Article 109672\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2025-07-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Mathematics Letters\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0893965925002228\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Mathematics Letters","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0893965925002228","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
A modified CMRH method for solving large nonsymmetric linear systems
This paper presents a modified CMRH method for solving large nonsymmetric linear systems. Based on the Hessenberg process, the proposed method requires less computation and storage compared to GMRES and QMR methods. The improvement involves utilizing the -th vector generated during the Hessenberg process to optimize the approximate solution through a linear combination, thereby reducing the number of matrix–vector multiplications and inner products. Theoretical analysis demonstrates that the improved CMRH method is more cost-effective than the original -step method. Numerical experiments validate the efficiency of the modified CMRH method across various test problems, showing fewer iterations and less computation time, particularly in large-scale problems.
期刊介绍:
The purpose of Applied Mathematics Letters is to provide a means of rapid publication for important but brief applied mathematical papers. The brief descriptions of any work involving a novel application or utilization of mathematics, or a development in the methodology of applied mathematics is a potential contribution for this journal. This journal''s focus is on applied mathematics topics based on differential equations and linear algebra. Priority will be given to submissions that are likely to appeal to a wide audience.