for loop to while loop

im trying to convert the code to while loop but im failing to see the mistake

%% while loop
clc
clear
x=16

x = 16

X=[0,10,15,20,22.5,30]

X = 1×6

0 10.0000 15.0000 20.0000 22.5000 30.0000

Y=[0,227.04,362.78,517.35,602.97,901.67]

Y = 1×6

0 227.0400 362.7800 517.3500 602.9700 901.6700

D=length(X)

D = 6

j=1

j = 1

j1=1

j1 = 1

i=1

i = 1

while j<D
    
    z(i)=1
    
    
    while j1<D
        
        if i~=j
            z(i)=z(i)*(x-X(j))/(X(i)-X(j))
        end
       j1=j1+1 
    end
    z(i)=z(i)*Y(i)
    j=j+1
    i=i+1
end 

z = 1

j1 = 2

j1 = 3

j1 = 4

j1 = 5

j1 = 6

z = 0

j = 2

i = 2

z = 1×2

0 1

z = 1×2

0 227.0400

j = 3

i = 3

z = 1×3

0 227.0400 1.0000

z = 1×3

0 227.0400 362.7800

j = 4

i = 4

z = 1×4

0 227.0400 362.7800 1.0000

z = 1×4

0 227.0400 362.7800 517.3500

j = 5

i = 5

z = 1×5

0 227.0400 362.7800 517.3500 1.0000

z = 1×5

0 227.0400 362.7800 517.3500 602.9700

j = 6

i = 6

sum(z)

ans = 1.7101e+03

%% for loop
clc
clear
x=16

x = 16

X=[0,10,15,20,22.5,30]

X = 1×6

0 10.0000 15.0000 20.0000 22.5000 30.0000

Y=[0,227.04,362.78,517.35,602.97,901.67]

Y = 1×6

0 227.0400 362.7800 517.3500 602.9700 901.6700

D=length(X)

D = 6

for i=1:D
    z(i)=1
    for j=1:D
        if i~=j
            z(i)=z(i)*(x-X(j))/(X(i)-X(j))
        end
    end
    z(i)=z(i)*Y(i)
end 

z = 1

z = -0.6000

z = 0.0400

z = 0.0080

z = 0.0023

z = 0.0011

z = 0

z = 1×2

0 1

z = 1×2

0 1.6000

z = 1×2

0 -0.3200

z = 1×2

0 -0.1280

z = 1×2

0 -0.0666

z = 1×2

0 -0.0466

z = 1×2

0 -10.5782

z = 1×3

0 -10.5782 1.0000

z = 1×3

0 -10.5782 1.0667

z = 1×3

0 -10.5782 1.2800

z = 1×3

0 -10.5782 1.0240

z = 1×3

0 -10.5782 0.8875

z = 1×3

0 -10.5782 0.8283

z = 1×3

0 -10.5782 300.4915

z = 1×4

0 -10.5782 300.4915 1.0000

z = 1×4

0 -10.5782 300.4915 0.8000

z = 1×4

0 -10.5782 300.4915 0.4800

z = 1×4

0 -10.5782 300.4915 0.0960

z = 1×4

0 -10.5782 300.4915 0.2496

z = 1×4

0 -10.5782 300.4915 0.3494

z = 1×4

0 -10.5782 300.4915 180.7828

z = 1×5

0 -10.5782 300.4915 180.7828 1.0000

z = 1×5

0 -10.5782 300.4915 180.7828 0.7111

z = 1×5

0 -10.5782 300.4915 180.7828 0.3413

z = 1×5

0 -10.5782 300.4915 180.7828 0.0455

z = 1×5

0 -10.5782 300.4915 180.7828 -0.0728

z = 1×5

0 -10.5782 300.4915 180.7828 -0.1359

z = 1×5

0 -10.5782 300.4915 180.7828 -81.9596

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 1.0000

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 0.5333

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 0.1600

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 0.0107

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 -0.0043

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 0.0037

z = 1×6

0 -10.5782 300.4915 180.7828 -81.9596 3.3342

sum(z)

ans = 392.0706

Answer 1

[Eric Delgado]

Try this...

x=16;
X=[0,10,15,20,22.5,30];
Y=[0,227.04,362.78,517.35,602.97,901.67];
D=length(X);

% WHILE LOOPS
i=1;
while i <= D
    z1(i)=1;
    
    j = 1;
    while j <= D
        if i~=j
            z1(i) = z1(i) * (x-X(j))/(X(i)-X(j));
        end
       j = j+1;
    end
    z1(i) = z1(i)*Y(i);
        
    i=i+1;
end 

% FOR LOOPS
for i = 1:D
    z2(i) = 1;
    for j = 1:D
        if i ~= j
            z2(i) = z2(i) * (x-X(j))/(X(i)-X(j));
        end
    end
    z2(i) = z2(i)*Y(i);
end 

isequal(z1, z2)

ans = logical
   1