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map - Dynamic application of several polynomials


I know how to get the 'resulting image' (y) from the application of a certain function (f) (here represented as the coefficients of a polynomial) over a certain interval (x):


x = Range[27000]/27001.;


f = {25.62, -38.43, 21.81}/9;

y = Map[f[[1]]*#^3 + f[[2]]*#^2 + f[[3]]*# &, x];

ListPlot[y]

How do i get the 'resulting images' from the application of several polynomials (represented as its coefficients) over a certain interval (x)?


Considering the representation of those several polynomials to be something like:


polynomials = Map[

{9 + #[[1]] - #[[2]], -#[[1]], #[[2]]} &,
Flatten[Outer[
List,
{23.75, 28.02, 32.29, 36.56, 40.83, 45.1, 49.37, 53.64, 57.91, 62.18},
{13.48, 15.9, 18.33, 20.75, 23.17, 25.6, 28.02, 30.44, 32.87, 35.29}
],
1]
]/9;

Answer



A similar approach is to define a function



 Clear[x]; p[x_, {a_, b_, c_}] := (a x^3 + b x^2 + c x)/9;

and then build a table of polynomials. Using the variable polynomials from the OPs question, these could be plotted as


 Plot[Table[p[x, polynomials[[i]]], {i, 1, Length[polynomials]}], {x, 0, 1}]

This leads to substantially the same plot as belisarius, but there are a few differences. This uses Plot instead of ListPlot because it's plotting the polynomials instead of the sampled values of the polynomials. As a consequence, the polynomials are being plotted against the values of x rather than against the index of a list of x values.


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