Calculating mean and variance , iris dataset

I would like to calculate mean an variance for iris dataset(for the first species) . How can i clean my code! Make it two for loop (one loop for mean , one loop for variance?

 load fisheriris
 a=meas(1:50,1:end);
 a1=a(1:50,1);
 a2=a(1:50,2);
 a3=a(1:50,3);
 a4=a(1:50,4);

 s1=0;
 for i=1:50;
     s1=s1+a1(i);
 end
 mean1=s1/50

 s2=0;
 for j=1:50;
     s2=s2+a2(j);
 end
 mean2=s2/50

 s3=0;
 for k=1:50;
     s3=s3+a3(k);
 end
 mean3=s3/50

 s4=0;
 for l=1:50;
     s4=s4+a4(l);
 end
 mean4=s4/50

 means=[mean1,mean2,mean3,mean4]

 v1=0;
 for p=1:50;
     v1=v1+(a1(p)-mean1)^2;
 end
 var1=v1/49

 v2=0;
 for o=1:50;
     v2=v2+(a2(o)-mean2)^2;
 end
 var2=v2/49

v3=0;
for u=1:50;
   v3=v3+(a3(u)-mean3)^2;
end
var3=v3/49

v4=0;
for t=1:50;
   v4=v4+(a4(t)-mean4)^2;
end
var4=v4/49

 totalvar=[var1 var2 var3 var4]

Answer 1

[Kevin Holly]

Is there a reason why you aren't using the mean and var function?

load fisheriris
a=meas(1:50,1:end);
means = mean(a)

means = 1×4

5.0060 3.4280 1.4620 0.2460

totalvar = var(a)

totalvar = 1×4

0.1242 0.1437 0.0302 0.0111

[mary keshtkar]

Actually this is an university assignment that I should calculate mean and variance without using mean and var function.

[Kevin Holly]

load fisheriris
a=meas(1:50,1:end);

s=0;
for ii=1:50
    s = s+a(ii,:);
end
means = s/50

means = 1×4

5.0060 3.4280 1.4620 0.2460

v=0;
for jj = 1:50
    v=v+(a(jj,:)-means).^2;
end
totalvar = v/49

totalvar = 1×4

0.1242 0.1437 0.0302 0.0111

[Kevin Holly]

Also, if you are allowed to use sum function:

load fisheriris
a=meas(1:50,1:end);
means = sum(a(1:50,:))/50

means = 1×4

5.0060 3.4280 1.4620 0.2460

totalvar = sum((a(1:50,:)-means).^2)/49

totalvar = 1×4

0.1242 0.1437 0.0302 0.0111

[NALLARASU KRISH]

Why divided by 49? It should be divided by 50 to calculate varience, right?