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Blitz Support : |
From: Othmar Frey (ofrey_at_[hidden])
Date: 2004-07-16 10:05:35
Hi.
I am rather new to blitz++.
I would like to evaluate a one dimensional array
at indices that are given in a - let's say - 2-dimensional
array of indices.
What I would love to have working is something like:
(something I am really fond of that it works in Matlab)
-------------------------------------------------------
...
Array<float,1> dataVector(100);
Array<float,2> dataMatrix1(20,20);
Array<float,2> dataMatrix2(20,20);
Array<int,2> arrayOfIndices(20,20);
...
// fill dataVector and dataMatrix1 with some data
// and set the indices in arrayOfIndices according to my needs
...
dataMatrix2 = dataMatrix1 + dataVector(arrayOfIndices);
...
---------------------------------------------------------
I've learned from the example pick.cpp at
http://www.oonumerics.org/blitz/examples/blitz/pick.cpp
that there's a possibility to pick
values from a vector according to a given index vector by using
VectorPick.
But then, all the nice elementwise operators don't work as the do for
arrays.
Is there straightforward solution to this problem, which I missed?
(Maybe one that is even mentioned in the documentation?)
Many thanks for your help.
Cheers
Othmar
-- ----------------------------------------------------------------------- Othmar Frey Remote Sensing Laboratories RSL ofrey_at_[hidden] University of Zurich http://www.geo.unizh.ch/~ofrey Winterthurerstrasse 190 phone +41 44 635 51 64 CH-8057 Zurich fax +41 44 635 68 46 Switzerland -----------------------------------------------------------------------