第四章 框图Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.l 框图是表示一个系统各部分和各环节 之间关系的图示，它的作用在于能够清晰 地表达比较复杂的系统各部分之间的关系 。l 本章将学习用“流程图”“结构图”等刻 画数学问题以及其他问题的解决过程；体 验用框图表示数学问题解决过程以及事物 发生、发展过程的优越性，提高抽象概括 能力和逻辑思维能力，能清晰地表达和交 流思想。 什么是框图Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.框图的分类框图流程图 （动态）结构图 （静态）Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.4.1 流程图Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.流程图 （一个起点）程序框图 （一个终点）其他流程图 （一个或多个终点）画程序框图程序框图与算 法步骤的比较生活、工业生产 中的流程图数学中的 流程图图书借阅流程图 诊病流程图画流程图 （单流程、双流程）读流程图 （工序流程图）证明方法 解题思路Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.4.1 流程图设计算法解决问题的主要步骤： 第一步、用自然语言描述算法；算法可以用自然语言来描述，但为了使算法的程 序或步骤表达得更为直观，我们更经常地用图形方 式来表示它。 第二步、画出程序框图表达算法； 第三步、写出计算机相应的程序并上机实现。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明：问题一：求方程x2-2=0的近似根。1、你能回忆一下用自然语言描述 的用二分法求方程x2-2=0的近似 根的算法步骤吗？必修3 P3例2Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明2、怎样用程序框 图表达算法步骤 中的“第一步？”输入误差 和 的初值1、2Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明：3、第二步中有哪些操作？其中包 含了哪些逻辑结构？怎样用程序 框图表达？条件结构Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明：是否第三步输出Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明4、第三步中是什么逻辑结构？怎 样用程序框图表达？条件结构Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明：是否第三步Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明5、第四步中是什么逻辑结构？怎 样用程序框图表达？循环结构Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.举例说明第二步第三步输出Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.输入误差 和 的初值是否输出是否是否Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.程序框图的特点和本质及不足P78特点:用程序框图表示的算法,比用自然语 言描述的算法更加直观、明确、流向清楚 ，而且更容易改写成计算机程序，本质：程序框图就是算法步骤的直观图示。不足：不能轻易地从中分解出算法的本 步骤。作用：可以直观、明确地表示动态过程从开始 到结束的全部步骤。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.你能说说绘制流程图的一般过程吗？l首先，用自然语言描述流程步骤；l其次，分析每一步骤是否可以直接表 达，或需要借助于逻辑结构来表达；l再次，分析各步骤之间的关系；l最后，画出流程图表示整个流程。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.图书馆借书流程图：入库出库找书借书阅览还书Evaluation only.Evaluation only. Created with