Need help getting a code to solve for a variable changing in size with a matching number of equations

CODE:

clear;
clc;
%Given;
L = 1;
k = 28;
h = 45;
M = 5;
Eqn = zeros(1,M);
T = zeros(1,M);
q_gen = 1*(10^5);
T(1) = -196;
T_infite = 30;
%Loops
m = 2;
while m <= M
    X = 0:L/(M-1):L;
    if m < M 
        Eqn(m) = ((T(m-1) -2*T(m) + T(m+1))/(X(m)^2)) * (q_gen/k) == 0;
        T(m) = solve(Eqn(m), T);
    elseif m == M
        Eqn(m) = h*(T_infite - T(1)) + k* ((T(m) - T(m+1))/X) * (q_gen*X/2) == 0;
        T(m) = solve(Eqn(m), T);
    end
    m = m+1;
end
plot(T);

ERROR:

Check for incorrect argument data type or missing argument in call to function 'solve'.

Error in Project (line 21)

T(m) = solve(Eqn(m), T);

Answer 1

[Walter Roberson]

q_gen = 1*(10^5);

Numeric

T(1) = -196;

That is a specific numeric value.

    X = 0:L/(M-1):L;

That is a vector of numeric values. (Note: consider using linspace instead. And move it to before the loop since it does not change.)

    Eqn(m) = ((T(m-1) -2*T(m) + T(m+1))/(X(m)^2)) * (q_gen/k) == 0

Everything on the left hand side is numeric, with no symbolic variables at all. This will be a calculated numeric value "==" 0, which is going to immediately evaluate to true or false, not to an equation.

    T(m) = solve(Eqn(m), T);

Eqn(m) is numeric and T is numeric. There is no solve() function that accepts two numeric values.

[Michael]

Okay. So how can I write this code to solve for T(m) given the eqations?

[Michael]

clear;

clc;

%Given;

L = 1;

k = 28;

h = 45;

M = 5;

Eqn = zeros(1,M);

q_gen = 1*(10^5);

T_n = -196;

T_infite = 30;

X = 0:L/(M-1):L;

%Loops

m = 2;

while m <= M

syms T

if m == 2;

Eqn(m) = ((T_n -2*T(m) + T(m+1))/(X(m)^2)) * (q_gen/k) == 0;

T_n = solve(Eqn(m), T);

elseif m > 2 && m < M

T_n = ((T_n -2*T(m) + T(m+1))/(X(m)^2)) * (q_gen/k) == 0;

elseif m == M

Eqn(m) = h*(T_infite - T_n) + k* ((T(m) - T(m+1))/X) * (q_gen*X/2) == 0;

T_n = solve(Eqn(m), T);

end

T_m(m) = T_n;

m = m+1;

end

plot(T_m,X);

Could this code potentially work instead if I fix the indexing error?