How to Execute Parallel program through SPMD or BATCH or TASK?

2012 6 29
1 个回答
回答已采纳
1 次查看（30 天）

0 个投票

Hi Everybody,
I need one Help From You.I want to execute my code parallel using SPMD. But not able to Run It. Already I was try to parfor Loop But I don't Know how to classify the Variable. So now I am try to run parallel through SPMD concept. But this program Run in same duration for each worker. But i want to split the work and run parallel.
This is my sample code
Otherwise how can I Run parallel program through TASK or BATCH. Thank You so much.

请先登录，再回答此问题。

 采纳的回答

Edric Ellis
Edric Ellis 2012-6-29

2 个投票

Inside an SPMD block, you need to use a for-loop over a distributed range.
In short
spmd
for i1=drange(1:n)
...
end
end

5 个评论
显示 3更早的评论 隐藏 3更早的评论

PRIYANGA
PRIYANGA 2012-7-2
But The SPMD concept doesn't accept the Global variable sir, How can I declare the Global variable sir? and How can I gather the distributed variable sir?
Walter Roberson
Walter Roberson 2012-7-2
What global variable are you referring to? Your Question does not have any global variables noted in it.
PRIYANGA
PRIYANGA 2012-7-13
编辑：Walter Roberson 2012-7-13
Sir, My starting prgm....
clc;
close all;
clear global oldrand;
clear global jrand;
clear all;
warning ('off','all');
spmd
global oldrand;
global jrand;
tic;
% read the image
im1=imread('C:\Program Files\MATLAB\PIC\lena.jpg');
c = im2uint8(im1);
% Split the R-G-B Component
R=c(:,:,1);
G=c(:,:,2);
B=c(:,:,3);
seedval=.5;
oldrand(55)=seedval;
newrand=.000001;
prevrand=seedval;
for j=1:54
i=floor(21*j / 55);
k=21*j-i*55;
oldrand(k)=newrand;
newrand=prevrand-newrand;
if (newrand<0.0)
newrand=newrand+1;
end
prevrand=oldrand(k);
end
advancerandom;
advancerandom;
advancerandom;
jrand=0;
end
That above code advancerandom is a function , its contain the global variable, but spmd concept not contain global variable so how can i declare the global variable in SPMD concept?
thank you sir..
Walter Roberson
Walter Roberson 2012-7-13
What result are you hoping to get out in "oldrand", considering that each of the spmd blocks is trying to write in the same set of locations, oldrand(1:55) ? Are you expecting to get a series of "oldrand" arrays out, one per lab? Are you expecting that "oldrand" will be self-consistent and containing only values from the "last" lab that gets executed? Are you expecting that "oldrand" will have a frightful mess of values, depending, location by location, on exactly which of the labs happens to write to each of the locations last, a matter which will differ from location to location ?
Though perhaps I am being too harsh, as there is no evidence in what you show that you are actually using any randomization at all: your "random" values are just sequential values .000001 smaller each time, and so would be the same for all the labs. As you do exactly the same thing in every lab, you might as well remove the spmd block and just do the activity once.

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Parallel for-Loops (parfor) 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