Using Arrays inside arrayfun()

10 次查看（过去 30 天）
MR
MR 2017-12-23
回答： Joss Knight 2017-12-26
I'm using gpuArrays with arrayfun to speed up calculations, and I would need to pass an array inside the call, as such
[Zn] = arrayfun( @iterFuncDelta,Xo,Yo,orbit)
function [Zn] = iterFuncDelta(xdelta0,ydelta0,refOrbit)
maxIterations=2^15;
delta=complex(xdelta0,ydelta0);
delta0=delta;
n=2;
Zn=refOrbit(1,1)+delta;
while ( n <= maxIterations )
Zn=refOrbit(n,1)+delta;
delta=2*refOrbit(n,1)*delta+delta^2+delta0;
n=n+1;
end
end
How could I pass the array 'orbit' so that it is not treated as a single point (like Xo and Yo) ?
Thanks.

请先登录，再回答此问题。

采纳的回答

Matt J
Matt J 2017-12-23
编辑：Matt J 2017-12-23
According to this example, it should be possible with a nested function. Not sure how fast it's likely to be, though.
function Outer(Xo,Yo,orbit) %EDIT
refOrbit=orbit;
function [Zn] = iterFuncDelta(xdelta0,ydelta0)
maxIterations=2^15;
delta=complex(xdelta0,ydelta0);
delta0=delta;
n=2;
Zn=refOrbit(1,1)+delta;
while ( n <= maxIterations )
Zn=refOrbit(n,1)+delta;
delta=2*refOrbit(n,1)*delta+delta^2+delta0;
n=n+1;
end
end
[Zn] = arrayfun( @iterFuncDelta,Xo,Yo);
end
  2 个评论
MR
MR 2017-12-23
But in that case, how does the arrayfun() call get access to the arrays Xo and Yo?
Matt J
Matt J 2017-12-23
编辑：Matt J 2017-12-23
You would pass that to Outer() as well (see edit). I of course can't know what other variables you actually have in your workspace, nor how they got there. The inclusion of Outer() was just an example to show the nested context needed for iterFuncDelta.

请先登录，再进行评论。

更多回答（2 个）

Walter Roberson
Walter Roberson 2017-12-23
  3 个评论
显示 1更早的评论
Walter Roberson
Walter Roberson 2017-12-23
[Zn] = arrayfun( @(x,y) iterFuncDelta(x,y,orbit), Xo, Yo )
Matt J
Matt J 2017-12-24
I don't think this will work on the GPU.

请先登录，再进行评论。

Joss Knight
Joss Knight 2017-12-26
You can't do any array or matrix operations in a GPU arrayfun kernel. You can access the contents of an array that is present as an up-level variable such as has been demonstrated in the comments. You can then loop over the contents of the array one element at a time, to emulate array operations such as a dot product. This blog article gives an example of doing this for a simple 3-vector.

类别

在 Help Center 和 File Exchange 中查找有关 GPU Computing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by