How to solve "Not enough input arguments."

function pinaka = pendatiagonal(e,c,d,a,b)

pinaka = pendatiagonal(e,c,d,a,b)

n = 7;

e = [0 0 round(10*rand(1,n-2))+1];

c = [0 round(10*rand(1,n-1))+1];

d = round(10*rand(1,n))+1;

a = [round(10*rand(1,n-1))+1 0];

b = [round(10*rand(1,n-2))+1 0 0];

e = e(3:end);

c = c(2:end);

a = a(1:end-1);

b = b(1:end-2);

diag(e,-2) + diag(c,-1) + diag(d,0) + diag(a,1) + diag(b,2);

disp(pinaka)

end

[Jon]

It isn't clear at all what you are doing here.

It looks like you start out defining a function call pendatiagonal, but then in the next line you call it, then you start assigning the input variable you would need for calling this function. What exactly are you trying to do, please explain further.

[Torsten]

@Dimitra comment moved here:

Hi,

i try to make a pendatiagonal matrix, which has zeros in all columns except the main diagonal and the 2 lines above and below it. The problem is that, when i run it , it says that

"Not enough input arguments."

Answer 1

[cdawg]

you're creating e, c, d, a, and b within the function.. it looks like n could be the only input. is this what you're trying to do?

n = 7;
pinaka = pendatiagonal(n)

pinaka = 7×7

9 2 1 0 0 0 0 7 7 4 3 0 0 0 9 8 3 5 6 0 0 0 8 10 5 10 9 0 0 0 3 5 3 9 3 0 0 0 1 6 9 4 0 0 0 0 3 1 10

function pinaka = pendatiagonal(n)
e = [0 0 round(10*rand(1,n-2))+1];
c = [0 round(10*rand(1,n-1))+1];
d = round(10*rand(1,n))+1;
a = [round(10*rand(1,n-1))+1 0];
b = [round(10*rand(1,n-2))+1 0 0];
e = e(3:end);
c = c(2:end);
a = a(1:end-1);
b = b(1:end-2);
pinaka = diag(e,-2) + diag(c,-1) + diag(d,0) + diag(a,1)  + diag(b,2);

end

Answer 2

[Jon]

You could also do it all with a very simple loop

pentadiagonal(7)

ans = 7×7

1 3 6 0 0 0 0 6 2 7 8 0 0 0 7 3 5 1 4 0 0 0 4 8 6 3 2 0 0 0 4 9 8 7 3 0 0 0 10 6 6 4 0 0 0 0 7 9 1

function pinaka = pentadiagonal(n)
pinaka = zeros(n,n); 
    for k = -2:2
        pinaka = pinaka + diag(randi(10,n-abs(k),1),k);
    end
end