Representation of this vector T_d1 and Td_2 in MATLAB

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For this information I tried to write the Td_2 in MATLAB
% Function to compute Stirling numbers of the first kind
function S = stirling1(n, k)
if n == k
S = 1;
elseif k == 0
S = 0;
elseif n == 0
S = 0;
else
S = stirling1(n-1, k-1) - (n-1) * stirling1(n-1, k);
end
end
% Pre-allocate the matrix T_d^2
T_d2 = zeros(M, M);
% Fill the matrix according to the Stirling number formula
for i = 1:M
for j = 1:i
T_d2(i, j) = stirling1(i, j); % Stirling number of the first kind
end
end
disp('Matrix T_d^2:');
disp(T_d2);
The results show Matrix T_d^2:
1 0 0 0
-1 1 0 0
2 -3 1 0
-6 11 -6 1
Td_1 as % Pre-allocate the matrix T_d^1
T_d1 = zeros(M, M);
% Fill the matrix according to the formula
for i = 1:M
for j = 1:i % j ranges from 1 to i
T_d1(i, j) = nchoosek(i-1, j-1) * ((-M + 1) / 2)^(i-j);
end
end
disp('Matrix T_d^1:');
disp(T_d1);
The results are Matrix T_d^1:
1.0000 0 0 0
-1.5000 1.0000 0 0
2.2500 -3.0000 1.0000 0
-3.3750 6.7500 -4.5000 1.0000
Is it a correct method of calculation ? Please could you give suggestions or comments ?

采纳的回答

Ashok
Ashok 2024-10-21,8:27
The provided code indeed calculates the and matrices based on the given formula. Here's an alternative approach that doesn't require declaring 'stirling1' as a separate function.
function Td1 = compute_Td1(M)
% Create a matrix of binomial coefficients
[I, J] = ndgrid(1:M, 1:M);
binomials = zeros(M, M);
for i = 1:M
binomials(i, 1:i) = arrayfun(@(ii, jj) nchoosek(ii-1, jj-1), I(i, 1:i), J(i, 1:i));
end
% Create a matrix for powers
powers = ((- (M - 1) / 2) .^ (I - J)) .* (J <= I);
% Element-wise multiplication to get Td1
Td1 = binomials .* powers;
end
function Td2 = compute_Td2(M)
% Initialize Td2 with identity
Td2 = eye(M+1);
for n = 2:M+1
for k = 2:n-1
Td2(n, k) = Td2(n-1, k-1) - (n-2) * Td2(n-1, k);
end
end
Td2 = Td2(2:M+1, 2:M+1);
end
% Example usage:
Td1 = compute_Td1(M);
disp('T_d^1:');
disp(Td1);
Td2 = compute_Td2(M);
disp('T_d^2:');
disp(Td2);
Additionally, for implementing cross products, consider using MATLAB's 'cross' function instead of nested for loops. You can find the relevant documentation here:
I believe this will be of use!

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