My Grading program is not printing the answers onto the text file

I have an assignment in which it is asking this

The file testscores.dat (testscores.txt) has on each line a student ID# and a test score. Write a program to read in the scores and use built-in MATLAB functions to determine the high, low, average (Ave), and the standard deviation (SD) of the scores. For each student, determine the grade assuming that the following table is used:

Print out in a new file (FinalGrades.txt or FinalGrades.dat) the student ID and the corresponding letter grade only. Your program must work for any properly formatted file named testscores.dat/txt. The program will also provide a summary of the scores: Low, High, Average, Standard Deviation, and the number of each letter grade to the command window

However my program that I have set up is not printing out anything onto the finalgrades file.

data=load('testscores.txt','r');
StudentID=data(:,1);
Scores=data(:,2);
SD=std(Scores);
Ave=mean(Scores);
A=0;
B=0;
C=0;
D=0;
F=0;
High=0;
Average=0;
Low=0;
FID=fopen('FinalGrades.txt','w');
if Scores>=Ave+1.5*SD
    A=A+1;
    High=High+1;
    fprintf(FID,'%d        A\n',StudentID);
elseif Ave+1.5*SD>Scores>=Ave+0.5*SD
    B=B+1;
    High=High+1;
    fprintf(FID,'%d        B\n',StudentID);
elseif Ave+0.5*SD>Scores>=Ave-0.5*SD
    C=C+1;
    Average=Average+1;
    fprintf(FID,'%d        C\n',StudentID);
elseif Ave-0.5*SD>Scores>=Ave-1.5*SD
    D=D+1;
    Low=Low+1;
    fprintf(FID,'%d        D\n',StudentID);
elseif Ave-1.5*SD>Scores
    F=F+1;
    Low=Low+1;
    fprintf(FID,'%d        F\n',StudentID);
end
fprintf('The number of low scores was %d\n',Low);
fprintf('The number of average scores was %d\n',Average);
fprintf('The number of high scores was %d\n',High);
fprintf('The number of As was %d\n',A);
fprintf('The number of Bs was %d\n',B);
fprintf('The number of Cs was %d\n',C);
fprintf('The number of Ds was %d\n',D);
fprintf('The number of Fs was %d\n',F);
fprintf('The Standard Deviation was %0.4f\n',SD);
fclose(FID);

The text file it is to read from is below in a two column set up

100014     88.3
100109     96.9
100205     69.9
100263     90.5
100269     86.9
100293     76.2
100329     81.9
100412     87.1
100414    108.4
100419    103.1
100436     75.9
100501    104.8
100575     89.6
100640     84.4
100686     89.5
100741     83.4
100771     84.0
100846     94.6
100865     94.1
100934     94.2
100953     89.2
100990     76.8
101053     89.5
101132     95.6
101141     88.0
101234     91.6
101312     89.6
101361     82.8
101405     86.7
101450     79.6
101481     90.7
101532     77.2
101584     77.7
101666     79.5
101746     65.4
101811     94.3
101849     86.9
101931     79.8
101985     93.8
102021     73.5
102115     84.1
102203     83.2
102259     86.9
102322     86.9
102381     79.1
102402     84.6
102433     83.7
102481     88.9
102505     92.0
102590     92.1
102610     79.1
102633     85.3
102651     76.8
102674     77.5
102718     84.8
102750     94.9
102843     79.7
102887     87.3
102906     83.3
102997     92.2
103095     77.6
103139     85.0
103151     88.4
103177     92.1
103218     95.0
103278     85.4
103305     75.0
103366     79.9
103438     77.8
103461    100.3
103473     80.7
103503     89.7
103535     83.5
103578     90.7
103629     79.8
103638     75.5
103665     75.4
103746     88.0
103749     83.6
103842     83.5
103916     94.2
103965     86.7
104023     86.1
104047     95.3
104093     79.5
104190     62.7
104245     63.6
104298     56.8
104322     59.7
104371     51.0
104434     51.1
104502     59.0
104542     62.9
104579     74.6
104678     54.1
104682     59.5
104771     57.8
104863     46.1
104943     55.5
104953     47.0
104980     63.6
105014     52.7
105082     58.9
105096     54.9
105169     60.2
105180     54.5
105246     61.4
105296     63.0
105374     69.1
105446     57.1
105537     44.8
105627     53.0
105661     66.8
105731     51.5
105751     64.4
105755     59.1
105830     67.4
105881     45.9
105929     57.1
106020     50.7
106081     76.6
106143     63.5
106229     67.0
106310     51.6
106368     55.3
106387     56.6
106411     65.2
106500     56.5
106503     62.7
106552     45.4
106569     56.1
106667     53.1
106739     48.4
106790     61.5
106838     60.1
106844     58.5
106913     49.9
106918     65.4
106926     60.5
106979     56.4
106989     58.4
107071     56.6
107153     47.3
107226     56.5
107241     53.1
107307     52.1
107359     51.0
107457     54.9
107522     45.7
107603     64.4
107649     61.6
107693     58.2
107776     58.1
107785     53.3
107799     64.7
107817     57.5
107857     53.8
107941     66.8
108022     56.9
108029     54.6
108069     56.4
108122     53.0

Any help would be much appreciated!!!

Answer 1

[Star Strider]

There are different ways to do this, however the easiest may be to put it in a loop:

for k = 1:numel(Scores)
    if Scores(k)>=Ave+1.5*SD
        A=A+1;
        High=High+1;
        fprintf(FID,'%d        A\n',StudentID(k));
    ... CODE ...
end

I leave the rest to you.

[Holden]

I tried setting up the loop but i still couldnt get it to print to the other file

[Holden]

In fact, im not even getting any results for the Number of High scores, Average Scores, Low Scores, or Letter Grades. All ive got is the standard deviation.

[Star Strider]

Post this as a new question, and with significantly more information.

Answer 2

[Walter Roberson]

if Ave+1.5*SD>Scores>=Ave+0.5*SD

In MATLAB that is parsed as

if all((Ave+1.5*SD>Scores)>=Ave+0.5*SD)

That is, Ave+1.5*SD>Scores is evaluated to a logical array, and the results in the logical array are compared to Ave+0.5*SD . false is converted to numeric 0, true is converted to numeric 1, and those 0 and 1 are compared >= Ave+0.5*SD. Probably the results will all be false. But unless all of the results are non-zero (true) then MATLAB will consider the test to be false.

You should fix your conditions. You might also wish to consider using logical indexing instead of looping.