% Example of How to Import Stock Statistics from Web into Matlab
% --- This example retrieves trailing P/E ratio from Yahoo! Finance
% LuminousLogic.com


% Initialize Workspace
function trailing_pe = get_trailing_pe(stock_symbol)

stock_symbol = upper(stock_symbol);

% Open connection to Yahoo! Finance statistics page
fprintf(1,'Retrieving trailing P/E ratio for %s...', stock_symbol);
url_name = strcat('http://finance.yahoo.com/q/ks?s=',  stock_symbol);
url     = java.net.URL(url_name);        % Construct a URL object
is      = openStream(url);              % Open a connection to the URL
isr     = java.io.InputStreamReader(is);
br      = java.io.BufferedReader(isr);

% Cycle through the source code until we find trailing P/E...
while 1
    line_buff = char(readLine(br));
    ptr       = strfind(line_buff, 'Trailing P/E');
    
    % ...And break when we find it
    if length(ptr) > 0,break; end
    
    % Handle the case where either data not available or no trailing PE
    no_data   = strfind(line_buff, 'There is no');
    if length(no_data) > 0, 
        fprintf(1,'Yahoo! Finance does not currently have trailing P/E for %s.\n',stock_symbol);
        trailing_pe = NaN;
        return; 
    end
end

% Just to make it easier, strip off all the preceeding stuff we don't want
line_buff   = line_buff(ptr:end);

% Extract the trailing P/E
ptr_gt      = strfind(line_buff,'>');
ptr_lt      = strfind(line_buff,'<');
trailing_pe = str2num(line_buff(ptr_gt(2)+1:ptr_lt(3)-1));
if length(trailing_pe) == 0
    fprintf(1,'N/A\n');
else
    fprintf(1,' = %3.2f\n', trailing_pe);
end