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Re: Generating a vector from successive multiplications of another vector from an initial value

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On Thu, Oct 1, 2015 at 2:45 PM, Paulo da Silva
<p_s_d_a_s_i_l_v_a_ns@netcabo.pt> wrote:
> Hi all.
>
> What is the fastest way to do the following:
>
> I have an initial value V and a vector vec of (financial) indexes.
> I want to generate a new vector nvec as
>
> V, V*vec[0], V*vec[0]*vec[1], V*vec[0]*vec[1]*vec[2], ...
>
> A numpy vectorized solution would be better.

That looks hard to vectorize since each calculation depends on the
previous. You might be stuck with something like:

result = [V]
for x in vec:
    result.append(result[-1] * x)

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Generating a vector from successive multiplications of another vector from an initial value Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2015-10-01 21:45 +0100
  Re: Generating a vector from successive multiplications of another vector from an initial value Ian Kelly <ian.g.kelly@gmail.com> - 2015-10-01 15:10 -0600
  Re: Generating a vector from successive multiplications of another vector from an initial value duncan smith <buzzard@invalid.invalid> - 2015-10-02 00:44 +0100
  Re: Generating a vector from successive multiplications of another vector from an initial value Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2015-10-02 02:01 +0100

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