<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">AM</journal-id><journal-title-group><journal-title>Applied Mathematics</journal-title></journal-title-group><issn pub-type="epub">2152-7385</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/am.2012.36076</article-id><article-id pub-id-type="publisher-id">AM-20071</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  A Note on a Recent Paper by J. S. Respondek
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>oawwad</surname><given-names>E. A. El-Mikkawy</given-names></name><xref ref-type="aff" rid="aff1"><sub>1</sub></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib></contrib-group><aff id="aff1"><label>1</label><addr-line>Faculty of Science, Mathematics Department, Mansoura University, Mansoura, Egypt</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>m_elmikkawy@yahoo.com</email></corresp></author-notes><pub-date pub-type="epub"><day>21</day><month>06</month><year>2012</year></pub-date><volume>03</volume><issue>06</issue><fpage>509</fpage><lpage>510</lpage><history><date date-type="received"><day>February</day>	<month>9,</month>	<year>2012</year></date><date date-type="rev-recd"><day>April</day>	<month>26,</month>	<year>2012</year>	</date><date date-type="accepted"><day>May</day>	<month>4,</month>	<year>2012</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  In this note, we give comments on a very recent paper by J. S. Respondek [1]. In [1], the author claims that an algorithm in [2] contains a severe error. We show that the algorithm in [2] can be implemented properly without causing any errors by using vectors (one-dimensional arrays) rather than using 2-dimensional arrays. To enable users and programmers of the algorithm to carry out the computations using all existing subscripts and superscripts in the algorithm, we give a correction in the first line of the algorithm. A Maple implementation for the algorithm, as it is in [2], is given as an example for symbolic programming.
 
</p></abstract><kwd-group><kwd>Elementary Symmetric Function; Algorithm; Maple; Symbolic Programming</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction and Objectives</title><p>For convenience of the reader, we begin this section by introducing the following abstract from [<xref ref-type="bibr" rid="scirp.20071-ref1">1</xref>] concerning the algorithm in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>].</p><p>“In this paper, we give the comments on the article ‘Inversion of a Generalized Vandermonde Matrix’ by M. E. A. El Mikkawy, Int. J. Computer Math. 80 (2003), pp. 759-765. The article gives an algorithm for the elementary symmetric function’s calculation which contains a severe error. In these comments, we have proposed necessary corrections of that algorithm”.</p><p>Let us begin our discussion by giving the following definition and the algorithm for the elementary symmetric function’s in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>]:</p><p>Definition 1.1 ([<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>], p. 760). If the n parameters <img src="1-7400753\e185585f-c369-4b4e-8c25-f83745376931.jpg" /> are distinct, then the elementary symmetric functions <img src="1-7400753\6add62d9-3982-4397-99f7-3825bc8eaf4e.jpg" /> in <img src="1-7400753\8c1d2d82-99fc-4c6d-8ce2-88b3e0b0d012.jpg" /> are defined for j = 1(1) n by:</p><p><img src="1-7400753\233d3f17-ae31-4c95-8828-eb532ffe1abf.jpg" /></p><p><img src="1-7400753\072d7ac8-c50d-4bdf-a8b4-27b6224906bf.jpg" />for i = 2(1) n.(1.1)</p><p>Denote by:</p><disp-formula id="scirp.20071-formula9997"><label>(1.2)</label><graphic position="anchor" xlink:href="1-7400753\2b56e196-9ac5-4026-a078-e2a10318d5ff.jpg"  xlink:type="simple"/></disp-formula><p>Algorithm (Algorithm 2.1 in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>], p. 760). For<img src="1-7400753\aa1324ec-c540-434c-8566-accafa31224e.jpg" />, we may calculate the elements of the first column of the n &#215; n matrix <img src="1-7400753\42c710c8-5853-4b47-b358-bfe8036ce832.jpg" /> in (1.2) as follows:</p><p>Set <img src="1-7400753\9596e29f-019f-44a3-b0bd-564f4951ec0f.jpg" /></p><p>For i = 2, 3, ∙∙∙, n</p><disp-formula id="scirp.20071-formula9998"><label>(1.3)</label><graphic position="anchor" xlink:href="1-7400753\5205d91c-09b3-4429-9231-053d74971b7f.jpg"  xlink:type="simple"/></disp-formula><p><img src="1-7400753\ae088061-099a-4b88-a771-e40542f27178.jpg" /></p><p>Next j Next i The elements in the remaining n − 1 columns of <img src="1-7400753\e225f71a-ca9e-497b-9ff0-fa2cb157e794.jpg" /> may be obtained by symmetry using</p><p><img src="1-7400753\61ac7575-d4dd-4aeb-8e60-85f0b9dea7d2.jpg" />, i = 1(1)n, k = 2(1)n. (1.4)</p><p>The notation in (1.4) means that for specific i and k, <img src="1-7400753\107a66aa-c101-4cfb-aa2e-db58f139847f.jpg" />may be obtained from the algebraic expression of <img src="1-7400753\99a19ecd-384c-447c-a878-73c5adcb9689.jpg" />by replacing each <img src="1-7400753\b1c126d1-1478-4826-a8cd-82959f3913c3.jpg" /> by <img src="1-7400753\809c5f3a-144c-422c-bb11-c08bdb690437.jpg" /> in the expression of <img src="1-7400753\a758ae9e-376a-49a7-bd43-372d0298a69e.jpg" />. <img src="1-7400753\fe05492c-6bef-4781-a3c4-32799510e652.jpg" /></p><p>In [<xref ref-type="bibr" rid="scirp.20071-ref1">1</xref>], Respondek claims that the above algorithm contains a severe error. In the next section, we are going to show that the algorithm, as it is in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>] and (1.3), can be implemented properly without causing any errors by using vectors (one-dimensional arrays) rather than using 2-dimensional arrays. To enable users and programmers of the algorithm to carry out the computations using all existing subscripts and superscripts in the algorithm, we give a correction in the first line of the algorithm. A Maple implementation for the algorithm, as it is in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>] and (1.3), is given as an example for symbolic programming.</p></sec><sec id="s2"><title>2. Main Results</title><p>It is now time to show that the algorithm, as it is in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>] and (1.3), can be implemented properly without causing any errors by using vectors (one-dimensional arrays) rather than using 2-dimensional arrays. The following is a Maple implementation for the algorithm in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>] and (1.3). Some sample output for the case n = 4 is given.</p><p>&gt; #&#160; Implementation of Algorithm 2.1 in [<xref ref-type="bibr" rid="scirp.20071-ref2">2</xref>], p. 760</p><p>&gt; restart:</p><p>&gt; n:=4: g :=array(1..n):</p><p>&gt; g[<xref ref-type="bibr" rid="scirp.20071-ref1">1</xref>]:=1:</p><p>&gt; for i from 2 to n do</p><p>&#160;&#160; g[i]:= c[i] * g[i-1]:</p><p>&#160;&#160; for j from i-1 to 2 by -1 do</p><p>&#160;&#160;&#160; &#160;&#160;g[j] := simplify(g[j] + c[i] * g[j-1]);</p><p>&#160;&#160; od:</p><p>od:</p><p>&gt; sigma := array(1..n,1..n):</p><p>&gt; for i to n do sigma[i,1] := g[i] ; od:</p><p>&gt; for i to n do</p><p>&#160;&#160; for j from 2 to n do</p><p>&#160;&#160;&#160;&#160;&#160; sigma[i,j] := subs({c[j]=c[<xref ref-type="bibr" rid="scirp.20071-ref1">1</xref>]},sigma[i,1]);</p><p>&#160;&#160; od:</p><p>od:</p><p>&gt; sigma = op(sigma);</p><p><img src="1-7400753\9e2d3936-7208-4564-88f1-8c1d089625d4.jpg" /></p><p>To enable users and programmers of the algorithm to carry out the computations using all existing subscripts and superscripts in the algorithm, as actually done by J. S. Respondek [<xref ref-type="bibr" rid="scirp.20071-ref1">1</xref>], we give a correction in the first line of the algorithm. The modified algorithm is now given by:</p><p>A Modified Algorithm. For <img src="1-7400753\5c96426a-b783-4ff8-b5be-94780af56af3.jpg" /> we may calculate the elements of the first column of the n &#215; n matrix <img src="1-7400753\f8cacab4-e7c1-436a-91ef-db99ba636b88.jpg" /> in (1.2) as follows:</p><p>Set<img src="1-7400753\3bba6150-23cd-471d-ab65-d012504584b2.jpg" />, i = 1(1) n − 1.</p><p>For i = 2, 3, ∙∙∙, n</p><disp-formula id="scirp.20071-formula9999"><label>(2.1)</label><graphic position="anchor" xlink:href="1-7400753\a17e0907-771c-41b4-bd19-75f91addb5fa.jpg"  xlink:type="simple"/></disp-formula><p><img src="1-7400753\cac3dbc4-2529-42b1-94d5-1a4fefa107a7.jpg" /></p><p>Next j Next i</p></sec><sec id="s3"><title>REFERENCES</title></sec></body><back><ref-list><title>References</title><ref id="scirp.20071-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">J. S. Respondek, “Comments on ‘Inversion of a Generalized Vandermonde Matrix’ by M. E. A. El-Mikkawy,” International Journal of Computer Mathematics, Vol. 88, No. 1, 2011, pp. 3565-3568. 
doi:10.1080/00207160.2011.603413</mixed-citation></ref><ref id="scirp.20071-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">M. E. A. El-Mikkawy, “Inversion of a Generalized Vandermonde Matrix by M. E. A. El-Mikkawy,” International Journal of Computer Mathematics, Vol. 80, 2003, pp. 759-765. doi:10.1080/0020716021000059133</mixed-citation></ref></ref-list></back></article>