Can anyone help with my function?

I have this function that is suppose to create a report for a specific story, but it keeps giving me an error when I try to run the function in the command window. Can anyone lead me in the right direction as to what im doing wrong?

function generateReport(storyTitle, numUniqueWords, topTenWords)
% uses the word data to create a report for specific story
% Input: numUniqueWords - integer for the number of unique words in the
%                         story being analysed
%        topTenWords - a 1x10 structure Array of the most frequent words
% Output: a report stored in a .txt file called storyReport.txt 

fid = fopen('StoryReport.txt', 'w'); % used to open/load report
fprintf(fid, 'Story Analyzed: %s\n',storyTitle);
fprintf(fid, 'Total Unique Words: %f\n', numUniqueWords);
fprintf(fid, 'Frequency, Word\n');
for i = 1:10 
    fprintf(fid, '%f, %s\n', topTenWords.frequency{i}, topTenWords.word{1});
end
fclose('storyReport.txt');

Answer 1

[Walter Roberson]

for i = 1:10 
    fprintf(fid, '%f, %s\n', topTenWords(i).frequency, topTenWords(i).word);
end

[Brian Leon]

I implemented this to my code and then I got this error.