I need help with normalization in java, my method is not properly ignoring zeros and im not sure why, here is the method: protected void normalizeRatingsByUser$($List ratings$)\{$

for $($int user $=0$; user $<$ ratings.get$(0).$length; user$++)\{$

double sum $=0$;

int count $=0$;

for $($double$[]$ rating : ratings$)\{$

if $($rating$[$user$]!=0)\{$

sum $+=$ rating$[$user$]$;

count$++$;

$\}$

$\}$

if $($count $>0)\{$

double mean $=$ sum $/$ count;

for $($double$[]$ rating : ratings$)\{$

if $($rating$[$user$]!=0)\{$

rating$[$user$]-=$ mean;

$\}$

$\}$

$\}$

$\}$

$\}$ and here is my unit test: @Test

public void testNormalizationIgnoresZeros$()\{$

Project.SongClusterer clusterer $=$ new Project.SongClusterer$()$;

List ratings $=$ Arrays.asList$($

new double$[]\{0,2,0,4\},$

new double$[]\{1,0,3,0\}$

$)$; and here is the output from the test: "Failed to map supported failure 'org.opentest$4$j$.$AssertionFailedError: Ratings should be normalized correctly ignoring zeros. $==>$ array contents differ at index $[3],$ expected: $<2\mathrm{.}0>$ but was: $<0\mathrm{.}0>\text{'}$ with mapper $"$ please help me fix my normalization im unsure why it wont ignore zeros properly and do not use chatgpt GPT$-4$ can not solve this problem otherwise i wouldnt be here, will upvote if you can help me get it working!