Matrix Trace
Matrix Trace
Compute the trace of a square matrix, defined as the sum of its diagonal elements.
Mathematical Definition
Trace of Matrix A:
tr(A)=i=1∑naiiwhere aii are the diagonal elements of matrix AA.
Function Arguments
A: 2D NumPy array, shape (N, N)- square matrix
Examples
Input: A = [[1, 2], [3, 4]]
Output: 5
Input: A = [[2, -1, 0], [3, 5, 1], [0, 2, -2]]
Output: 5 (trace = 2 + 5 + (-2))
Input: A = [[42]]
Output: 42
Hint 1
Use a loop to iterate through indices and accumulate A[i, i] for each diagonal element.
Hint 2
The number of diagonal elements equals A.shape[0] (or A.shape[1] for square matrices).
Requirements
- Return a single scalar (float or int)
- Do not use
np.trace()orA.diagonal().sum() - Compute manually via indexing or iteration
- Handle negative, zero, and float elements
- Handle 1x1 edge case
Constraints
- 1 ≤ N ≤ 1000
- Matrix elements can be any float or int
- Time limit: 100ms
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Accepts: array
Matrix Trace
Matrix Trace
Compute the trace of a square matrix, defined as the sum of its diagonal elements.
Mathematical Definition
Trace of Matrix A:
tr(A)=i=1∑naiiwhere aii are the diagonal elements of matrix AA.
Function Arguments
A: 2D NumPy array, shape (N, N)- square matrix
Examples
Input: A = [[1, 2], [3, 4]]
Output: 5
Input: A = [[2, -1, 0], [3, 5, 1], [0, 2, -2]]
Output: 5 (trace = 2 + 5 + (-2))
Input: A = [[42]]
Output: 42
Hint 1
Use a loop to iterate through indices and accumulate A[i, i] for each diagonal element.
Hint 2
The number of diagonal elements equals A.shape[0] (or A.shape[1] for square matrices).
Requirements
- Return a single scalar (float or int)
- Do not use
np.trace()orA.diagonal().sum() - Compute manually via indexing or iteration
- Handle negative, zero, and float elements
- Handle 1x1 edge case
Constraints
- 1 ≤ N ≤ 1000
- Matrix elements can be any float or int
- Time limit: 100ms
Try Similar Problems
Log in to take notes on this problem
Accepts: array