sec1-1.htm

Fortran77和90/95编程入门,用于教学

lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>用户在软件开发上的巨大投资，整个</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>被作为</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的一个严格子集。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal align=center style='margin-top:15.6pt;margin-right:0cm;
margin-bottom:15.6pt;margin-left:0cm;mso-para-margin-top:1.0gd;mso-para-margin-right:
0cm;mso-para-margin-bottom:1.0gd;mso-para-margin-left:0cm;text-align:center;
line-height:200%;text-autospace:none;mso-char-indent-size:10.5pt'><a
name="第1_1_2"><span lang=EN-US style='font-size:16.0pt;mso-bidi-font-size:12.0pt;
line-height:200%;mso-fareast-font-family:楷体_GB2312'>1.1.2</span></a><span
lang=EN-US style='font-size:16.0pt;mso-bidi-font-size:12.0pt;line-height:200%;
mso-fareast-font-family:楷体_GB2312'> <span style='color:red'>Fortran</span></span><span
lang=ZH-CN style='font-size:16.0pt;mso-bidi-font-size:12.0pt;line-height:200%;
font-family:楷体_GB2312;mso-ascii-font-family:"Times New Roman";color:red'>的新发展</span><span
lang=EN-US style='font-size:16.0pt;mso-bidi-font-size:12.0pt;line-height:200%;
mso-fareast-font-family:楷体_GB2312'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none;mso-char-indent-size:
10.5pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>随着其他程序设计语言的迅速发展，</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言不再是惟一适用的程序设计语言。然而，尽管在一些特殊领域，使用其他程序语言更为合适，但在数值计算、科学和工程技术领域，</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>仍具有强大的优势。其强大的生命力在于它能紧跟时代的发展，不断更新标准，每次新的文本推出都在功能上有一次突破性进展。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>不仅仅是将已有的语言进行标准化，更重要的是发展了</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言，吸取了一些其他语言的优点。所以，虽然</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言历史悠久，但仍在日新月异地发展。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none;mso-char-indent-size:
12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>随着巨型计算机</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>(</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>向量机和并行机</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的异军突起，出现了新的<span style='color:#993300'>高性能</span></span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;color:#993300'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>(HPF)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>，它是</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的一个扩展子集，主要用于分布式内存计算机上的编程，以减轻用户编写消息传递程序的负担。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>HPF-1.0</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的语言定义是在</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>1992</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>年的超级计算国际会议上<span class=GramE>作出</span>的，正式文本是在</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>1993</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>年公布的。其后几年的会议上又对它进行了修改、重定义、注释等工作，于</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>1997</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>年发布了</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>HPF2.0</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>语言定义。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>Fortran95</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>包含了许多</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>HPF</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的新功能。在</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>出现之前，在并行机上运行程序需要结合专门的矢量化子程序库，或者是依赖</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>编译系统进行自动矢量化。而</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>之后，程序员在编程时可有目的的控制并行化。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none'><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>在当前程序设计语言层出不穷的今天，学习</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言的意义在于继承传统和紧跟时代。不仅一些爱好者推崇</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>语言</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><a
href="pages/Real%20Programmers%20Don't%20Use%20Pascal.htm">[A Real Programmer]</a>
</span><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>，而且科学计算编程的专家也认为，科学与工程相关专业的学生应该采用</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>而非</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>C</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>C++</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>编程［</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><a
href="pages/Fortran%2090%20for%20Science%20Students.htm">F90 for Science
Student</a></span><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>］。这是因为，</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>具有</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>C++</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>所有的重要功能（尚不具备的预计将在</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran2k</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>版本中推出），然而</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>C</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>语言主要是用于微机上的廉价开发，而</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的目的是为了产生高效最优化运行的可执行程序，用</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>编写的大型科学计算软件较</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>C</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>语言编写的通常要快一个量级，其程序编写更为自然和高效，且易学易懂。尤其是在高性能并行计算逐渐成为时代必然的今天，不仅巨型<span
class=GramE>机而且</span>微机和工作站也有了多处理器，其串行机上的线性内存模式已不再适用，而只有</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>具备处理相应问题的标准并行化语言，其独特的数组操作充分体现了它的先进性。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>C++</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>语言的比较可参看</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>: <a
href="http://csep1.phy.ornl.gov/csep.html">http://csep1.phy.ornl.gov/csep.html</a></span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo4;
tab-stops:list 18.0pt;text-autospace:none'><a name="第1_1_2a"></a><![if !supportLists]><span
lang=EN-US style='font-family:宋体;mso-bidi-font-family:宋体;color:red'><span
style='mso-list:Ignore'>a)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span class=GramE><span lang=EN-US
style='font-family:宋体;color:red'>Fortran77 </span><b style='mso-bidi-font-weight:
normal'><span lang=EN-US style='font-size:20.0pt;font-family:宋体;color:red'>?</span></b></span><span
lang=EN-US style='font-family:宋体;color:red'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none;mso-char-indent-size:
12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>既然已经有了</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>，那么是否就不用学习</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>了？事实上，由于很多用户在</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>程序上作了巨大的投资，许多大型科学计算</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>程序</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>(</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>有些长达数十万条语句</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>，如分子动力学模拟计算</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体;color:black'>(C60-C240</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体;color:black'>的碰撞：</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;color:black'><a
href="movie/cc010.mpg">10eV</a></span><span lang=ZH-CN style='font-size:12.0pt;
font-family:宋体;color:black'>，</span><span lang=EN-US style='font-size:12.0pt;
font-family:宋体;color:black'><a href="movie/cc100.mpg">100eV</a></span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体;color:black'>，</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;color:black'><a
href="movie/cc300.mpg">300eV</a>)</span><span lang=ZH-CN style='font-size:12.0pt;
font-family:宋体'>等程序仍在频繁地使用。在科技领域内某些标准程序库（</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>International Mathematics and <span
class=SpellE>Statics</span> Library, Numerical Algorithms Group</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>）内有数千以上的子程序是用</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>写的，特别是早期的程序都是用</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>编写的，这些程序库已通过长期使用验证了稳定性。科学研究经常需要使用或改编以前的程序，这时必须了解</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的编程手法。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none'><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>因此，本教程仍然将</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>作为基础，但随时与</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>比较不同之处。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo4;
tab-stops:list 18.0pt;text-autospace:none'><a name="第1_1_2b"></a><![if !supportLists]><span
lang=EN-US style='font-family:宋体;mso-bidi-font-family:宋体;color:red'><span
style='mso-list:Ignore'>b)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span class=GramE><span lang=EN-US
style='font-family:宋体;color:red'>Fortran90 </span><b style='mso-bidi-font-weight:
normal'><span lang=EN-US style='font-size:20.0pt;font-family:宋体;color:red'>!</span></b></span><span
lang=EN-US style='font-family:宋体;color:red'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;text-autospace:none;mso-char-indent-size:
12pt'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>并没有删去任何</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的功能，而只是将某些功能看成是将要摒弃的。在</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran95</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>中则是已被删去的，但考虑到历史，厂家推出的</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90/95</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>编译软件仍是支持这些功能的。在新编的程序中，应尽量避免使用过时的</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>F77</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>语句或功能。目前已有一些软件可将这些功能除去并自动转换成并行化的程序。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90/95</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>是具有强烈现代特色的语言，总结了现代软件的要求与算法应用的发展，增加了许多现代特征的新概念、新功能、新结构、新形式。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran90</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的现代特性表现在：</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:47.25pt;text-autospace:
none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>加强了程序的可读性、可维护性：淘汰所有转移语句，用新的控制结构实现选择分叉与重复操作，使程序结构化。同时增加了结构块、模块及过程的调用灵活形式，使程序易读易维护，新的模块装配取代了</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran77</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>的许多旧语句，使程序员更为清晰明确地定义全局数据。增加了新的数据种别说明，使得</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>程序在不同计算机编译环境下有更自由的移植性。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:47.25pt;text-autospace:
none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>发展了现代算法功能：加强了数组的算法功能，引进了多种数组操作功能与概念，使数组像一个变量一样自由操作，使数组的并行化运算成为可能。增加了适于操作数据结构的派生类型，提高了文字处理功能，胜任信息管理系统、办公自动化的任务。特别是动态存储功能的引进极大地加强了它在数值计算领域中应用的威力。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:47.25pt;text-autospace:
none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>扩大与编程者的友好界面：新的编程形式减少了烦琐与格式束缚，接近自然语言与公式演算。允许在字符数据中选取不同种别，在字符串中可使用各国文字（例如汉字），还可任意使用化学、物理、数学的各种专业字符。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

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