unable to plot this equation

t=1:20;

a(1)=1;

b(1)=1;

c(1)=1;

I=0.5;

a=1;b=3;

c=1;

d=5

r=0.0001;

s=4;

xr=-1.6

sumx=0;

sumy=0;

sumz=0;

for i=1:20

a(i+1)=(-a*a(i).^3+b*a(i).^2+b(i)-c(i)+I)/(i+1)

b(i+1)=(c-d*a(i)^2-b(i))/(i+1);

c(i+1)=r*((s*(a(i)-xr)-c(i)))/(i+1);

sumx=sumx+a(i)*t.^i;

sumy=sumy+b(i).*t.^i;

sumz=sumz+c(i).*t.^i;

end

plot(t,sumx)

[Arif Hoq]

why are using a for loop for indexing ?

all of your variable is a scalar element. Try this code

t=1:20;
I=0.5;
a=1;b=3;
c=1;
d=5;
r=0.0001;
s=4;
xr=-1.6;
sumx=0;
sumy=0;
sumz=0;
 for i=1:20   
A=(-a*a.^3+b*a.^2+b-c+I)/(i+1);
B=(c-d*a^2-b)/(i+1);
C=r*((s*(a-xr)-c))/(i+1);
    sumx=sumx+A*t.^i;
    sumy=sumy+B.*t.^i;     
    sumz=sumz+C.*t.^i; 
 end
plot(t,sumx)

[shiv gaur]

no a(i) came from derivation of power series this is not avoid

[Arif Hoq]

so what is the value of a ? it can not be a scalar.here a =1. it should be a vector or matrix

[shiv gaur]

so a is the vector you can take a is the parameter scalar a(i) is the vector so you can take replacement as a=m

for simplicity edit program is here

t=1:20;

a(1)=1;

b(1)=1;

c(1)=1;

I=0.5;

m=1;b=3;

c=1;

d=5

r=0.0001;

s=4;

xr=-1.6

sumx=0;

sumy=0;

sumz=0;

for i=1:20

a(i+1)=(-m*a(i).^3+b*a(i).^2+b(i)-c(i)+I)/(i+1)

b(i+1)=(c-d*a(i)^2-b(i))/(i+1);

c(i+1)=r*((s*(a(i)-xr)-c(i)))/(i+1);

sumx=sumx+a(i)*t.^i;

sumy=sumy+b(i).*t.^i;

sumz=sumz+c(i).*t.^i;

end

plot(t,sumx)

Answer 1

[Arif Hoq]

i have considered the variable with random number

t=1:20;
I=0.5;
a=randi(20,1,20);
b=randi(30,1,20);
c=randi(30,1,20);
m=1;
d=5;
r=0.0001;
s=4;
xr=-1.6;
sumx=0;
sumy=0;
sumz=0;
C=cell(1,3);
 for i=1:20   
C{i,1}=(-m*a(i).^3+b*a(i).^2+b(i)-c(i)+I)/(i+1);
C{i,2}=(c-d*a(i)^2-b(i))/(i+1);
C{i,3}=r*((s*(a(i)-xr)-c(i)))/(i+1);
    sumx=sumx+C{i,1}.*t.^i;
    sumy=sumy+C{i,2}.*t.^i;     
    sumz=sumz+C{i,3}.*t.^i; 
 end
plot(t,sumx)

[shiv gaur]

so you are req to plot as same value not random value

[Arif Hoq]

do you mean?

a =ones(1,20,1)

a = 1×20

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

b=repmat([2 2 2 2 2],1,4)

b = 1×20

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

c=repmat([3 3 3 3 3],1,4)

c = 1×20

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3