{"title":"Rational interpolation method for solving initial value problems (IVPs) in ordinary differential equations","authors":"Anetor Osemenkhian","doi":"10.1016/j.jnnms.2014.05.001","DOIUrl":null,"url":null,"abstract":"<div><p>In this paper we designed Rational Interpolation Method for solving Ordinary Differential Equations (ODES) and Stiff initial value problems (IVPs).</p><p>This was achieved by considering the Rational Interpolation Formula. <span><span><span><math><msub><mrow><mi>y</mi></mrow><mrow><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></msub><mo>=</mo><msub><mrow><mi>U</mi></mrow><mrow><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></msub><mo>=</mo><mfrac><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>+</mo><msub><mrow><mi>P</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msup><mrow><mi>P</mi></mrow><mrow><mn>3</mn></mrow></msup><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>+</mo><msub><mrow><mi>p</mi></mrow><mrow><mn>4</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>+</mo><msub><mrow><mi>P</mi></mrow><mrow><mn>5</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>5</mn></mrow></msup></mrow><mrow><mn>1</mn><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>x</mi><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>3</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>4</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>5</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>5</mn></mrow></msup><mo>+</mo><msub><mrow><mi>q</mi></mrow><mrow><mn>6</mn></mrow></msub><msup><mrow><mi>x</mi></mrow><mrow><mn>6</mn></mrow></msup></mrow></mfrac><mtext>,</mtext></math></span></span></span> satisfying <span><math><mi>U</mi><mrow><mo>(</mo><msub><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>+</mo><mi>i</mi></mrow></msub><mo>)</mo></mrow><mo>=</mo><msub><mrow><mi>y</mi></mrow><mrow><mi>n</mi><mo>+</mo><mi>i</mi></mrow></msub><mo>,</mo><mi>i</mi><mo>=</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>,</mo><mn>4</mn><mo>,</mo><mn>5</mn><mo>,</mo><mn>6</mn></math></span>.</p><p>We also implemented <span><math><mi>k</mi><mo>=</mo><mn>6</mn></math></span> in Aashikpelokhai (1991) class of rational integration formulas given by <span><span><span><math><msub><mrow><mi>y</mi></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msub><mo>=</mo><mfrac><mrow><munderover><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mn>0</mn></mrow><mrow><mn>5</mn></mrow></munderover><msub><mrow><mi>p</mi></mrow><mrow><mi>i</mi></mrow></msub><msubsup><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow><mrow><mi>i</mi></mrow></msubsup></mrow><mrow><mn>1</mn><mo>+</mo><munderover><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mrow><mn>6</mn></mrow></munderover><msub><mrow><mi>q</mi></mrow><mrow><mi>i</mi></mrow></msub><msubsup><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow><mrow><mi>i</mi></mrow></msubsup></mrow></mfrac></math></span></span></span> where, <span><span><span><span><math><mtext><mglyph></mglyph></mtext></math></span></span><span><span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>j</mi></mrow></msub><mo>=</mo><mfrac><mrow><munderover><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mrow><mi>j</mi></mrow></munderover><msup><mrow><mi>h</mi></mrow><mrow><mrow><mo>(</mo><mi>j</mi><mo>+</mo><mn>1</mn><mo>−</mo><mi>i</mi><mo>)</mo></mrow></mrow></msup><msubsup><mrow><mi>y</mi></mrow><mrow><mi>n</mi></mrow><mrow><mrow><mo>(</mo><mi>j</mi><mo>+</mo><mn>1</mn><mo>−</mo><mi>i</mi><mo>)</mo></mrow></mrow></msubsup></mrow><mrow><munderover><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mrow><mi>j</mi></mrow></munderover><mrow><mo>(</mo><mi>j</mi><mo>+</mo><mn>1</mn><mo>−</mo><mi>i</mi><mo>)</mo></mrow><mi>!</mi><msubsup><mrow><mi>X</mi></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow><mrow><mrow><mo>(</mo><mi>j</mi><mo>+</mo><mn>1</mn><mo>−</mo><mi>i</mi><mo>)</mo></mrow></mrow></msubsup></mrow></mfrac><msub><mrow><mi>q</mi></mrow><mrow><mi>i</mi><mo>−</mo><mn>1</mn></mrow></msub><mo>+</mo><msub><mrow><mi>y</mi></mrow><mrow><mi>n</mi></mrow></msub><msub><mrow><mi>q</mi></mrow><mrow><mi>j</mi></mrow></msub><mtext>,</mtext><mspace></mspace><mi>j</mi><mo>=</mo><mn>1</mn><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mn>5</mn><mtext>.</mtext></math></span></span></span></span> The results as analyzed with the computer show that the rational interpolation method copes favorably well with ordinary differential equations and stiff initial value problems.</p></div>","PeriodicalId":17275,"journal":{"name":"Journal of the Nigerian Mathematical Society","volume":"34 1","pages":"Pages 83-93"},"PeriodicalIF":0.0000,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jnnms.2014.05.001","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Nigerian Mathematical Society","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0189896514000055","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
In this paper we designed Rational Interpolation Method for solving Ordinary Differential Equations (ODES) and Stiff initial value problems (IVPs).
This was achieved by considering the Rational Interpolation Formula. satisfying .
We also implemented in Aashikpelokhai (1991) class of rational integration formulas given by where, The results as analyzed with the computer show that the rational interpolation method copes favorably well with ordinary differential equations and stiff initial value problems.