Calling a function with a loop

I am calling a function that is one .m file from another .m file. Anytime I want to call the "Single" function I get error messages. What am I doing wrong here? Can someone debug my code please?

Thank you in advance!

File 1: Main program

data_set= importdata('/Users/.../Desktop/Fall2018/6214_AssetPotfolio/Assignment1/Return_data_import_Assignment1.xlsx');
%importing data from the root directory%

indexdata = data_set.data(:,1:2);
%grabbing and renaming the date column and the SPXT data column 
%(:, 1:2)- all rows and columns 1 and 2  
indexdata(:,1) = x2mdate(indexdata(:,1));
%converting the data format into a Matlab Data format%
%(:, 1)- all rows and first column "#x2mdate" command

return_data = indexdata;
%rename the spxtdata as return_data

annual_factor=12; 
rolling_window=12;
%these are used to annualize the data
%rolling window to compute the rolling returns

Single (return_data, annual_factor,rolling_window)

%Calling the function which inputs the return data vector annulization
%factor and the rolling window values

File 2: Function

function results= Single (return_data, annual_factor, rolling_window)
%funtion name is defined as follows:
%function name (variables inputs which are locally defined-see below)

%This function calculates the statistics for a single vector
%The input variables in the function are:
%return data: nx2 vector with date in col1, monthly returns in col2
%annual factor: 12 which is the number of periods used to annualize the values
%rolling window: the number of periods used to compute the rolling returns, 
%i.e 12 in this case

%Outputs:
%results.Stats: Column vector of the 5 basic stats: (1) Annulized Returns, (2)
%Annulaized Volatility, (3) Return to Risk Ratio, (4) Maximum Drawdown
%Value, (5) Max 1 Year Loss
%results.labels: A matrix of dates and rolling "rolling_window"period returns

%Main program for the function:

gross_return=cumprod(return_data(:,2)+1);
%gross cumulative returns calculated
obs=size(return_data,1);
%number of observations in the data

annual_return=gross_return(end)^(annual_factor/obs)-1;
%annualized formula of the gross return

annual_volatility = sqrt(annual_factor)*std(return_data(:,2));
%annualizing the value of the volatility 

risk_return=annual_return/annual_volatility;
%the risk to return ratio is calculated

MaxDD=maxdrawdown(gross_return);
%maximum drawdown is calculated using built in function 

no_periods=obs-rolling_window+1;
%the number of periods

rolling_year=zeros(no_periods, 2);
%the rolling year zero matrix is used to store the rolling year values

for i=1:no_periods
    total_cumulprod= cumprod(return_data(1:1+annual_factor-1,2)+1);
    rolling_year (i,1)=return_data(1+annual_factor-1,1);
    rolling_year(i,2)=total_cumulprod(end)-1;

end

max1yrloss=min(rolling_year(:, 2));

results.Stats=[annual_return; annual_volatility; risk_return, MaxDD; max1yrloss];
results.Rollyr=rolling_year;
results.labels={"Annual Return"; "Annual Volatility"; "Risk to Return"; 
    "Maximum Drawdown"; "Max 1year Loss"};
end

[Walter Roberson]

What is the complete error message?

We do not have your data so we cannot test the code ourselves.

[Stephen23]

NeoGlobal007's "Answer" moved here:

I get various error messages which I suspect are all interrelated. I have attached the data file here. The data file is a xls file of the various stock indeax returns. I am taking a single return vector as an input (column 2 of data) and outputing the following indices as a matrix:

(1) annual_return=gross_return(end)^(annual_factor/obs)-1;
(2) annual_volatility = sqrt(annual_factor)*std(return_data(:,2));
(3) risk_return=annual_return/annual_volatility;
(4) MaxDD=maxdrawdown(gross_return);
(5) max1yrloss=min(rolling_year(:, 2))

Answer 1

[Walter Roberson]

You have

results.Stats=[annual_return; annual_volatility; risk_return, MaxDD; max1yrloss];

Notice the comma: it needs to be semi-colon.