Uniform approximation from Tchebycheff systems

dc.contributor.authorBrookes, Richard Gordon
dc.date.accessioned2015-07-27T23:18:37Z
dc.date.available2015-07-27T23:18:37Z
dc.date.issued1987en
dc.description.abstractThis report is concerned with the study of best uniform approximation to f E C[a,b) from the linear space generated by some finite subset U == {uo,u1, ... ,u} of C[a,b). n p* E span U such that By a best uniform approximation we mean max{jf(x) ~p*(x) j: x E [a,b]} = min{max{jf(x) -p(x) I x E [a,b]} : p E span u}. We explore, firstly, the case U = {l,x, ... ,xn}. It will be shown in Section 4 that in this situation each f E C[a,b) has a unique best approximation and for this best approximation there is a strong characterisation theorem. It is then natural to ask whether these results are true for a more general U = {u 0 ,u 1 , ••• ,u } . n If a strong type of linear independence known as the Haar condition is imposed on U then this will indeed turn out 1. to be the case. We will attempt to develop this condition using an approach more intuitively obvious than those found in many standard texts. When the Haar condition is not satisfied the problem rapidly becomes complicated and it appears that much work remains to be done in this area. A theorem concerning a particularly simple situation is given in Section 8.en
dc.identifier.urihttp://hdl.handle.net/10092/10705
dc.language.isoen
dc.publisherUniversity of Canterbury. Mathematicsen
dc.relation.isreferencedbyNZCUen
dc.rightsCopyright Richard Gordon Brookesen
dc.rights.urihttps://canterbury.libguides.com/rights/thesesen
dc.subject.anzsrcField of Research::01 - Mathematical Sciences::0101 - Pure Mathematicsen
dc.titleUniform approximation from Tchebycheff systemsen
thesis.degree.grantorUniversity of Canterburyen
thesis.degree.levelResearch Reporten
thesis.degree.nameResearch Reporten
uc.bibnumber218919en
uc.collegeFaculty of Engineeringen
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