I get error undefined function or variable 'n' but don't show the line number.

function BSpline_B=Coef(n,t,y,a)
int8 i;int8 n;real p;real q;real r;real s;
a=[];h=[];t=[];y=[];
for i=1:n-1
  h(i)=t(i)-t(i-1);
end
h(0)=h(1);
h(n+1)=h(n);
p=-1;
q=2*y(0);
r=p*q;
s=2;
for i=1:n
  e=h(i+1)/h(i);
  p=-e*p;
  q=-e*q+(e+1)*y(i);
  r=r+p*q;
  s=s+p.^2;
end
a(0)=r./s;
for i=1:n-+1
  a(i)= ((h(i-1)+h(i))*y(i-1)- (h(i)*a(i-1)))/(h(i-1));
end
end
function BSpline_B_Eval(n,t,a,h,x)
int8 i;int8 n;
real d;real e;real x;a=[];t=[];h=[];
for i=n-1:0
  if x-t(i)>=0
      break
  end
end
  i=i+1;
  d=(a(i+1)*(x-t(i-1))+a(i)*(t(i)-x+h(i)))./(h(i)+h(i+1));
  e= (a(i)*(x-(t(i-1)+h(i-1)))+a(i-1)*(t(i-1)-x+h(i)));
  BSpline_B_Eval= (d*(x-t(i-1))+e*(t(i)-x))/h(i);
 end
function BSpline_B_test()
int8 i;real e;real h;real x;
t=[];
y=[];
z=[];
n=41;
a=-1;
b=1;
q=(b-a)/n;
for i=0:n
  t(i)=a+i*h;
 y(i)=sin(t(i));
end
Coef(n,t,y,z)
temp=0;
for j=0:4*n
  x=a+j*h/4;
  e= abs(sin(x)-BSpline_B_Eval(n,t,y,z,x));
  if e> temp
      temp=e;
      disp(j+ e+ x);
  end
end
end

Answer 1

[Star Strider]

You have to call the function from a script, after you have defined values for all the arguments in your workspace:

n = ...;
t = ...;
y = ...;
a = ...;
BSpline_B = Coef(n,t,y,a);

You cannot run it correctly by clicking on the green Run triangle.