Histogram with adjusted bins to gaussian

I need to take the new histogram from this code and apply a gaussian but when I try to do so I get a gaussian over the unaltered histogram.

here is my code

[num,~,~]=xlsread('histogram2.xlsx');

d=num;

h = histogram(d,50)

%remove one count per bin for background estimate

h.BinCounts(h.BinCounts>0) = h.BinCounts(h.BinCounts>0)-1

h=histfit(d,50)

I dont know how to referance the histogram with the adjusted bins in the histfit function

I am on R2020a

Answer 1

[Tommy]

If you'd like to fit a histogram to a normal distribution but you don't know the underlying data (e.g. you've altered the histogram in some way), you could instead fit the bin centers and values to a Gaussian curve:

% create your histogram
[num,~,~]=xlsread('histogram2.xlsx');
d=num;
h = histogram(d,50)
h.BinCounts(h.BinCounts>0) = h.BinCounts(h.BinCounts>0)-1

% fit the Gaussian, based only on h
x = h.BinEdges(1:end-1)+h.BinWidth/2;
y = h.Values;
gaussian = @(mu, sig, scale, x) 1/(sig*sqrt(2*pi))*exp(-(((x-mu)/sig).^2)/2) * scale;
x0 = [mean(x), range(x), sum(h.Values*h.BinWidth)]; % guesses for [mu, sig, scale]
f = fit(x(:), y(:), gaussian, 'StartPoint', x0);

% plot the Gaussian on top of your histogram
hold on;
p = plot(f);
p.LineWidth = 2;

You can obtain the fit parameters with f.mu and f.sig. You may need to use a better starting point.

[daniel caltrider]

I tried the code but got this error

Check for missing argument or incorrect argument data type in call to function 'fit'.

[Tommy]

Hmm... what is your MATLAB version and what does this print?

which fit -all