How to plot a polynomial function multiplied by a row vector

Hello!

My question is how to make a function file which will plot a polynomial function p(x)=a0+ a1x^1 + a2x^2 + a3x^3 + .... + amx^m.

I know how to plot a polynomial function from this form: 1 + x + x^2 + x^3+ ... + x^M, which is for k = 0:M p = p + x.^k end; plot(x,p);

But I don't know how I can multiply the multiple parts with a certain variable.

Does anyone know how to do this?

Answer 1

[Thorsten]

for k = 0:M 
  p = p + a(k+1)*x.^k; 
end;

[Maud]

Thanks! But do you also know how to program it with a as a row vector? For example, when I need to make the function with a series of particular numbers as the variables, so when the number is 9870225, the polynomial function will be : 9 + 8x + 7x^2 + 0x^3 + 2x^4+ 2x^5 + 5x^6

[Thorsten]

You can generate the variable "a" from your number as follows

v = 9870225; 
N = ceil(log10(v)); 
for i = 1:N
  a(N-i+1) = rem(v, 10);
  v = floor(v/10);
end