cumprod MATLAB

Introduction

The cumprod function in MATLAB calculates the cumulative product of an array along a specified dimension. It returns an array of the same size as the input, where each element is the product of all elements preceding it along the specified dimension.

Syntax

B = cumprod(A)
B = cumprod(A,dim)

Arguments

• A: Input array
• dim (optional): Dimension along which to calculate the cumulative product. If not provided, the default value is the first non-singleton dimension.

Output

• B: Array of the same size as A containing the cumulative products.

Examples

Example 1

A = [1 2 3 4];
B = cumprod(A)

Output:

B = [1 2 6 24]

In this example, the cumulative product of the elements in array A is calculated, resulting in [1 2 6 24].

Example 2

A = [1 2 3; 4 5 6];
B = cumprod(A, 2)

Output:

B = [1 2 6; 4 20 120]

In this example, the cumulative product is calculated along the second dimension of array A. So, the output B is [1 2 6; 4 20 120], where the first row contains the cumulative products of the first row in A and the second row contains the cumulative products of the second row in A.

Example 3

A = [1 2 3; 4 5 6];
B = cumprod(A, 1)

Output:

B = [1 2 3; 4 10 18]

In this example, the cumulative product is calculated along the first dimension of array A. The output B is [1 2 3; 4 10 18], where the first column remains the same as A, and each element in the second column is the product of the corresponding elements in the first column and A.

Conclusion

The cumprod function in MATLAB is a useful tool for calculating the cumulative product along a specified dimension. It can be used to analyze trends, growth rates, and compute various statistical measures.