DSP Blockset

Cumulative Sum

Compute the cumulative sum of row or column elements.

Library

Math Functions / Math Operations

Description

The Cumulative Sum block computes the cumulative sum of the row or column elements in the M-by-N input matrix u.

Columnwise Summing

When the Cumulative Sum along parameter is set to Columns, the block computes the cumulative sum of the column elements.

y = cumsum(u)            % Equivalent MATLAB code

The output is an M-by-N matrix whose jth column has elements

The frame status of the output is the same as the input. For sample-based inputs, the first row of each successive output is the same as that of the corresponding input. For convenience, length-M 1-D vector inputs are treated as M-by-1 column vectors for column-wise summation, and the output is a length-M 1-D vector.

For frame-based inputs, the first row of the first output is the same as that of the first input, and the first row of each subsequent output contains the sum of the first row of the current input (time t) and the last row of the previous output (time t-T_f).

Rowwise Summing

When the Cumulative Sum along parameter is set to Rows, the block computes the cumulative sum of the row elements.

y = cumsum(u,2)          % Equivalent MATLAB code

The output is an M-by-N matrix whose ith row has elements

The frame status of the output is the same as the input. For both sample-based and frame-based inputs, the first column of each successive output is the same as that of the corresponding input. For convenience, length-N 1-D vector inputs are treated as 1-by-N row vectors for row-wise summation, and the output is a length-N 1-D vector.

Dialog Box

Cumulative Sum along

The dimension along which to compute the cumulative summations. Columns specifies columnwise summation, while Rows specifies rowwise summation.

See Also

Difference	DSP Blockset
Matrix Sum	DSP Blockset
cumsum	MATLAB

Create Diagonal Matrix

dB Conversion