Is there a convenient way to compute cumulative sums in Eigen, like the cumsum functions in Matlab and NumPy?

A vector cumsum would be something like:

Code: Select all

In [1]: a = arange(5)
In [2]: a.cumsum()
Out[2]: array([ 0,  1,  3,  6, 10])

or along a specific axis of an array:

Code: Select all

In [3]: A = arange(15).reshape((-1,3))
In [4]: A
Out[4]:
array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11],
       [12, 13, 14]])
In [5]: A.cumsum(0)
Out[5]:
array([[ 0,  1,  2],
       [ 3,  5,  7],
       [ 9, 12, 15],
       [18, 22, 26],
       [30, 35, 40]])

If there isn't an easy existing method, is there a natural way to extend Eigen with such an operation?

(By the way, thanks for the amazing library, and apologies if this is a newbie question!)

see this thread: viewtopic.php?f=74&t=95502