Need help with a problem

There is a program I have one part I have to modify, could anyone help with this?

function y = run (lambda, n_mea, n_smpls_per_mea)
global xacc  hist  bin_range  bin_size  n_bins  bin_size_inv  midpt  bin

% define parameters and procedures for histogram:
bin_range = 6.0 * lambda           %NOTE: prefactor can be changed
bin_size = 0.1 * lambda            %NOTE: prefactor can be changed
n_bins = floor(bin_range/bin_size)+1
bin_size_inv = 1.0/bin_size
%  bin is a function: bin(x) provides the bin number for x:
bin =@(x)(min(floor(x*bin_size_inv)+1,n_bins))
%  hist accumulates the number of entries in each bin:
hist = zeros(1,n_bins)
xacc = [n_mea]
for m=1:n_mea
      xacc(m)=0
      for n=1:n_smpls_per_mea
         % unifrnd(0,1)  gives a random uniform on (0,1) 
         ranxi = unifrnd(0,1)
         % ranexp gives exponential distribution 
         ranexp = ranxi
         %      *^^^^^^^^^ <-- MODIFY -- fill in correct form**
         xacc(m) = xacc(m) + ranexp
         bi = bin(ranexp)
         hist(bi) = hist(bi) +1
      end 
      xacc(m) = xacc(m)/n_smpls_per_mea
end
midpt = 0.5*bin_size:bin_size:(n_bins-0.5)*bin_size   

end

[OCDER]

Before we can attempt to help:

What do you need to modify?

What is the correct form?

 " *%      *^^^^^^^^^ <-- MODIFY -- fill in correct form**

What is the error message, if any?

Have you heard of camelcase notation of variables? It'll make codes easier to read because tracking underscores in variable names is just confusing. Read this https://en.wikiversity.org/wiki/CamelCase.

midpt = 0.5*bin_size:bin_size:(n_bins-0.5)*bin_size   

midpt = 0.5*binSize:binSize:(nBins-0.5)*binSize

Also:

• do not use hist as a variable name because hist is a matlab function.
• instead of unifrnd(0, 1), you could use rand() for a uniform number between 0 to 1.

[Jan]

You point out, where the changes should be applied, but do not explain with any detail, what you want to change. What is the "correct form"?

Do not call your function "run", because this is an important Matlab command.

[Gaëtan Poirier]

For the modification: the expression for the exponential random number generator ranexp in run

[OCDER]

Have you looked up this on the google search?

"matlab exponential distributed random number"

[Gaëtan Poirier]

Yes, I added histogram('Normalization','probability'); but seem to have the error "not enough input arguments."

[Jan]

Whenever you mention an error in the forum, post a complete copy of the message, not just a part of it.

[Gaëtan Poirier]

Error in mkhist (line 13) exact_pdf = exp(-x/lambda)/lambda;

[Walter Roberson]

mkhist is not called from the code that you posted.