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Author: hsz1273327

Python_Other_Topics/扩展与性能优化/mpi扩展(mpi4py)/mpi4py.ipynb

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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "mpi(Message Passing Interface的简称)，也就是消息传递,是c,c++,以及fortran下的并行框架,而[mpi4py](http://mpi4py.readthedocs.org/en/stable/)是它的python接口,pypy也可以使用呦\n",
+    "\n",
+    "安装它先要安装openmpi,然后安装numpy和cython\n",
+    "\n",
+    "## MPI的工作方式:\n",
+    "\n",
+    "MPI就是启动一组MPI进程，每个进程都是执行同样的代码,然后每个进程都有一个ID，也就是rank来标记自己。假设一个CPU是你请的一个工人，共有10个工人。你有100块砖头要搬，然后很公平，让每个工人搬10块。这时候，你把任务写到一个任务卡里面，让10个工人都执行这个任务卡中的任务，也就是搬砖！这个任务卡中的“搬砖”就是你写的代码。然后10个CPU执行同一段代码。需要注意的是，代码里面的所有变量都是每个进程独有的，虽然名字相同。简单的理解就是工作室魔兽多开刷金..."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "> 例: helloworld"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "collapsed": false
+   },
+   "source": [
+    "h1.py\n",
+    "\n",
+    "```python\n",
+    "from mpi4py import MPI\n",
+    "comm = MPI.COMM_WORLD\n",
+    "rank = comm.Get_rank()\n",
+    "print(\"hello world\")\n",
+    "print(\"my rank is:\",rank)\n",
+    "```"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "    mpirun –np 3 python h1.py"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Pypy",
+   "language": "python",
+   "name": "pypy"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.10"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}