How to fit a gaussian distribution curve on a bar diagram?

Hello guys!

I have pdf of sum of two dice like data = [1/36,2/36,3/36,4/36,5/36,6/36,5/36,4/36,3/36,2/36,1/36] and sum =[2,3,4,5,6,7,8,9,10,11,12] I have darwn a bar chart using data. now I want to fit a normal distribution curve over this bar chart. But when I did it normal curve is coming out very narrow how can I spread it so that all the bar will come under normal curve. here is my plots

can you please help me to figure out this.

any help will be appreciated!

[Matt J]

We don't know what you did to obtain the curve.

[Raushan]

here is my script

y =[1/36,2/36,3/36,4/36,5/36,6/36,5/36,4/36,3/36,2/36,1/36];

bar(y)

hold on

p = -3:0.01:3;

q = normpdf(p,0,0.1);

plot(p,q)

after doing this my bar diagram is not coming under the curve

Answer 1

[Chunru]

p = [1/36,2/36,3/36,4/36,5/36,6/36,5/36,4/36,3/36,2/36,1/36];
xsum =[2,3,4,5,6,7,8,9,10,11,12] ;
bar(xsum, p)
mu = sum(p.*xsum)

mu = 7.0000

sigma2 = sum(p.*(xsum -mu).^2)

sigma2 = 5.8333

hold on
plot(0:.1:13, normpdf(0:.1:13, mu, sqrt(sigma2)), 'r-')

[Raushan]

Thats great! but I can see the peak is not smooth in this plot is it possible to make it smooth.

I used histfit command in matlab and i got this

data =[.....]

histfit(data)

[Raushan]

@Chunru you are an expert! Thanks a lot!

[Raushan]

can we make these triangles smooth in the above plots?

[Chunru]

Yes. Just change the x grid as updated above.

[Raushan]

Thank you very much it works!!