Question

cubic spline program

Answer 1

program:

quadspline:=proc(x::Vector,y::Vector,t::name)
local n,k,S,j,eq,tt,s;
n:=LinearAlgebra:-Dimensions(x)-1;

for k from 1 to n do
s[k]:=a[k]*(t-x[k])^2+b[k]*(t-x[k])+c[k];
end do;

j:=0;

for k from 1 to n do
j:=j+1; eq[j]:=subs(t=x[k],s[k])=y[k];
j:=j+1; eq[j]:=subs(t=x[k+1],s[k])=y[k+1];
end do;

for k from 1 to n-1 do
j:=j+1; eq[j]:=subs(t=x[k+1],diff(s[k],t))=subs(t=x[k+1],diff(s[k+1],t));
end do;

j=j+1; eq[j]:=subs(t=x[1],diff(s[1],t,t))=2;

tt:=solve({seq(eq[j],j=1..4*n)},{seq(a[j],j=1..n),seq(b[j],j=1..n),seq(c[j],j=1..n)});
assign(tt);
S:=piecewise(seq(op([t>=x[k] and t<=x[k+1],s[k]]),k=1..n));
return S;
end proc

Answer 2

its the last problem on there

Answer 3

i keep getting that error message

Answer 4

did you open the pdf?

Answer 5

what pdf?

Answer 6

scroll all the way to the bottom to see the error message

Answer 7

({seq(eq[j],j=1..4*n)},{seq(a[j],j=1..n),seq(b[j],j=1..n),seq(c[j],j=1..n)})

strange parentheses here

Answer 8

yep I think it's that line...

Answer 9

i dont think so, thats is exactly how the prof. has it on his version of the program. What i want to know is what that error is

Answer 10

can't plot a, b,c etc

Answer 11

it's not passing the values it solved for but the names of the constants instead.