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z1[x_]:=(2416 - 1680 x^2 + 560 x^4 - 140 x^6 + 35 x^7)/5040;z2[x_]:=(2472 - 392 x - 504 x^2 - 1960 x^3 + 2520 x^4 - 1176 x^5 + 252 x^6 - 21 x^7)/5040;z3[x_]:=(-1112 + 12152 x - 19320 x^2 + 13720 x^3 - 5320 x^4 + 1176 x^5 - 140 x^6 + 7 x^7)/5040;z4[x_]:=(4-x)^7/5040;spl[x_ /; Abs[x] <= 1]:= z1[Abs[x]];spl[x_ /; Abs[x] > 1 && Abs[x] <= 2] := z2[Abs[x]];spl[x_ /; Abs[x] > 2 && Abs[x] <= 3] := z3[Abs[x]];spl[x_ /; Abs[x] > 3 && Abs[x] <= 4] := z4[Abs[x]];spl[x_ /; Abs[x] > 4] := 0;f[n_]:=Sum[(-1)^k (a z)^k,{k,0,n}] Sum[(-1)^k (a /z)^k,{k,0,n}] Sum[(-1)^k (b z)^k,{k,0,n}] Sum[(-1)^k (b /z)^k,{k,0,n}]Sum[(-1)^k (c z)^k,{k,0,n}] Sum[(-1)^k (c /z)^k,{k,0,n}]/df[100]/.{a->0.535281,b->0.122555,c->0.00914759,d->0.330597}Series[Expand[%],{z,0,15}]Simplify[2(Integrate[Cos[w x] z1[x],{x,0,1}]+ Integrate[Cos[w x] z2[x],{x,1,2}]+ Integrate[Cos[w x] z3[x],{x,2,3}]+ Integrate[Cos[w x] z4[x],{x,3,4}])/ (z1[0] + 2 z2[1] Cos[w] + 2 z3[2] Cos[2 w] + 2 z4[3] Cos[3 w])];Plot[Sum[SeriesCoefficient[%%,k] spl[x-k], {k,-15,15}],{x,-6,6}, PlotStyle->{Thickness[0.01]}, Frame->True,PlotRange->All, FrameLabel->{None,None,"B-spline interpolator: B-7",None}];Plot[%%,{w,-2Pi,2Pi},PlotStyle->{Thickness[0.01]}, Frame->True, FrameLabel->{None,None,"Spectrum",None}]; Show[GraphicsArray[{%%,%}]];Display["junk_ma.eps",%,"EPS",ImageSize->648];
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