[Ipopt] Number, Index types

Stefan Vigerske stefan at math.hu-berlin.de
Sat Jul 16 09:58:33 EDT 2016


Hi,

I think it's more of the latter.
There are some open tickets about using long instead of int for Index, 
which isn't easy for the same reasons: the interfaces to third-party 
libraries for linear algebra and system solvers would need to convert 
array contents, if Index != int or Number != double.

Stefan

On 07/15/2016 08:54 PM, Sean Hardesty wrote:
> I am working on optimization problems arising in seismic imaging where the
> number of significant digits in the data is small, and the size of the data
> is large. It is common practice to use 32-bit floating point numbers for
> optimization variables and 64-bit integers for indexing. I see the file
> IpTypes.hpp has typedefs for Number and Index. I tried changing Number to
> float and got compiler errors because other parts of the Ipopt code use
> double interchangeably with Number. I have not looked through the code, but
> I can see that there could be issues in interfacing with BLAS and linear
> solvers that would have to be handled carefully. Is there a simple way to
> make it work with the different types, or is the use of the Number and
> Index types more of an aspiration for the future?
>
>     Thanks,
>     Sean Hardesty
>
>
>
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