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// polyscale Scaling roots of a polynomial
// scales the roots of a polynomial in the z plane
//Syntax:
//b = polyscale(a,alpha)
// where
//a is the vector containing the polynomial coefficients
// alpha is the scaling vector
//
//EXAMPLES:
//to scale the seventh roots of unity ,x^7=1,
////we represent
//p=[1 0 0 0 0 0 0 -1] and changing the scaling factor,
//b=polyscale(p,0.85)
//EXPECTED OUTPUT:b=1. 0. 0. 0. 0. 0. 0. - 0.3205771
//p=[1 0 0 0 0 0 0 -1] and changing the scaling factor,
//b=polyscale(p,0.95)
//EXPECTED OUTPUT:b=1. 0. 0. 0. 0. 0. 0. - 0.6983373
//
//p=[1 0 0 0 0 0 0 -1] and changing the scaling factor,
//b=polyscale(p,1)
//EXPECTED OUTPUT:b=1. 0. 0. 0. 0. 0. -1
// Author
//Debdeep Dey
function b = polyscale(a,alpha)
//errcheck1
if(min(size(a))>1) then
error('Input polynomial must be an array')
end
if type(a)==10 then
error("Input cannot be of type char");
end
b = a .* (alpha .^ (0:length(a)-1));
endfunction
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