Re: [eigen] How to raise double to array powers in Eigen

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 18.08.2014 00:23, Ian Bell wrote:
> cross-posted to stack overflow...

If you cross-post, could you post a link as well?

> I need to raise a double value to an array of integer powers, in c++ this
> would look something like

Could you be a bit more specific about the "array of integer powers" (I 
guess 'exponents')?
If they are a sequence 0,1,2,3,... your proposed solution is definitely 
very inefficient. If they are of great range, with no apparent pattern, 
I would say the exp(log(delta)*exponent) approach is basically the most 
efficient solution (maybe using log2 and exp2 would be more efficient, 
if they were available).

Christoph


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Dipl.-Inf., Dipl.-Math. Christoph Hertzberg
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