How to change the answer into decimals

Hi all,

I wanted to ask about my result here. Usually it is in decimals but when i used poly2sym here it turned into fractions. How can I change it back to decimals? Thanks in advance

[Birdman]

Can you share your entire code? It is hard to tell what you tried to do here.

[Faris Sulam]

So i was basically trying to convert the answer of the folloing code into a polynomial form:

function [ p ] = UDPolyReg( x,y )
%UNTITLED2 Summary of this function goes here
%   Detailed explanation goes here
%y=[0 3 4.5 5.8 5.9 5.8 6.2 7.4 9.6 15.6 20.7 26.7 31.1 35.6 39.3 41.5]
n=length(x);
m=4;
for i=1:2*m
    xsum(i)=sum(x.^(i));
end
a(1,1)=n
b(1,1)=sum(y)
for j=2:m+1
    a(1,j)=xsum(j-1);
end
for i=2:m+1
    for j=1:m+1
        a(i,j)=xsum(j+i-2);
    end
    b(i,1)=sum(x.^(i-1).*y);
end
p=(a\b)'
for i=1:m+1
    FuncVal(i)=p(m+2-i);
end
Vstrain=0:0.1:6;
stressfit=polyval(FuncVal,Vstrain);
plot(x,y,'ro',Vstrain, stressfit)
xlabel('Strain')
ylabel('Stress')

end

Answer 1

[VBBV]

poly2sym converts numeric vector to vector of symbolic equation and by default it uses the variable x. The values in vector are treated as coefficient of symbolic polynomial in x.

[VBBV]

In your case vector has 5 values. So it results in polynomial in 4th power. MATLAB converted the numeric values to fractions and expressed in form of polynomial.

Use sym2poly to convert back to numeric vector.