Polynomials in Matlab - Plotting Results

[ineedhelpnow]

View attachment 5037

y = [0.053 1.477 1.970 3.279 4.153 4.934 5.178 5.828 6.082 6.484]; % data
coef = polyfit(x,y,3) 
X=0:.1:9;
Y=polyval(coef,X);
plot(x,y,'o',X,Y)

that's my code. did i do it right?

 

[Dethrone]

You need to define your $x$ values. This should be right:

y = [0.053 1.477 1.970 3.279 4.153 4.934 5.178 5.828 6.082 6.484]; % data
x = [0 1 2 3 4 5 6 7 8 9];
coef = polyfit(x,y,3) 
X=0:.1:9;
Y=polyval(coef,X);
plot(x,y,'o',X,Y)

Output:

View attachment 5038

You can add a title, legend, and axis labels if you want, using [m]title()[/m], [m]legend()[/m], [m]xlabel()[/m], [m]ylabel()[/m], respectively.

 

[ineedhelpnow]

i cut that part of the code out by mistake but i have it in there. i see it's the same graph though. thanks rido!