sec4-1.htm

fortran 教程

line-height:15.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>DATA<span
style='mso-spacerun:yes'>&nbsp; </span><span class=SpellE>cstuff</span>/(-1.0,-1.0)/<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;
tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><a name="第4_1_2"><span lang=EN-US style='font-size:16.0pt;
mso-bidi-font-size:12.0pt;mso-fareast-font-family:楷体_GB2312'>4.1.2</span></a><span
lang=EN-US style='font-size:16.0pt;mso-bidi-font-size:12.0pt;mso-fareast-font-family:
楷体_GB2312'> </span><span lang=ZH-CN style='font-size:16.0pt;mso-bidi-font-size:
12.0pt;font-family:楷体_GB2312;mso-ascii-font-family:"Times New Roman";
color:red'>种别说明</span><b><span lang=EN-US style='font-size:16.0pt;mso-bidi-font-size:
12.0pt;mso-fareast-font-family:楷体_GB2312'><o:p></o:p></span></b></p>

<p style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo4;
tab-stops:list 18.0pt;text-autospace:none;mso-char-indent-size:10.5pt'><a
name="第4_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
lang=ZH-CN style='font-family:宋体;color:red'>种别说明方法</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;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none;mso-char-indent-size:12pt'><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>种别是</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>F90</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的新概念。一个数据</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'>不仅有一个类型，并在同一类型下可分为若干种别，种别值确定了数据的大小范围和精度。有了种别说明后，程序更易于移植。因为在不同的计算机系统上，同一种变量类型可以有不同的精度，因此当程序在另一种机子上运行时可能出现溢出或下溢。规定种别后可以避免这种情况的出现。</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:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>我们知道，一个数据通常在内序中占一个存贮单元。对整型数而言，如果该变量在程序中使用值范围很小，则只需半个存贮单元。如果变量的整数变化范围很大，则存贮时有必要占两个内存单元。实型数更复杂，除了存贮的数值范围大小不同外，要求精度也会不同，有的只要</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>8</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>位有效值即满足，有的则可能要</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>24</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>位有效值。这样，它们要求的存贮单元数量不同。为了提高效率，节约内存，按照该变量表达的值范围与表达的精度范围，把同一类划分成几个种别，不同种别分配不同数目的内存单元。</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:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>国际标准</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'>版本没有规定每个类型必须有哪些种别，具体的种别划分由</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'>软件开发商自行设置。因此程序员在设计变量时，按该变量表达值的范围、精度要求范围，查阅手册，确定合适的种别，在说明语句中加以说明。</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:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>种别由种别选择符说明，写在类型关键字后括号内，其关键字是</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>KIND</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>，后跟</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'>号及种别值。其形式为：<span style='color:#FF9900'>类型说明</span></span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;color:#FF9900'>([KIND=]</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体;color:#FF9900'>种别值</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;color:#FF9900'>)</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 class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>例如要说明变量</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>X</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>是实型，种别值是</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>2</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>，说明语句是：</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:57.7pt;mso-char-indent-count:4.81;
line-height:15.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>REAL(KIND=2)::
X<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:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>一个变量必有一个种别，如果变量的类型说明语句中没有种别说明符，如：</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:57.7pt;mso-char-indent-count:4.81;
line-height:15.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>REAL::
X, Y<o:p></o:p></span></p>

<p class=MsoNormal style='line-height:17.0pt;mso-line-height-rule:exactly;
tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
text-autospace:none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>则表示变量</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>X</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'>Y</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的种别缺省，这时采用系统规定的标准值。</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:l1 level1 lfo4;
tab-stops:list 18.0pt;text-autospace:none'><a name="第4_1_2b"><![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 lang=ZH-CN style='font-family:宋体;
color:red'>种别值</span></a><span style='mso-bookmark:第4_1_2b'></span><span
lang=EN-US style='font-family:宋体;color:red'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:24.0pt;line-height:17.0pt;mso-line-height-rule:
exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-layout-grid-align:none;text-autospace:none;mso-char-indent-size:12pt'><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Compaq Fortran </span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>提供了如下几类种别值：</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-top:7.8pt;margin-right:0cm;margin-bottom:7.8pt;
margin-left:21.0pt;mso-para-margin-top:.5gd;mso-para-margin-right:0cm;
mso-para-margin-bottom:.5gd;mso-para-margin-left:2.0gd;line-height:17.0pt;
mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-layout-grid-align:none;text-autospace:none'><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>整数：有</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>4</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>种，种别值即为字节数</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>n</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>

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0
 style='margin-left:57.75pt;border-collapse:collapse;border:none;mso-border-top-alt:
 solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-right-alt:
 solid windowtext .5pt;mso-yfti-tbllook:480;mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
 mso-border-insideh:.5pt solid windowtext;mso-border-insidev:.5pt solid windowtext'>
 <tr style='mso-yfti-irow:0'>
  <td width=302 valign=top style='width:226.45pt;border:solid windowtext 1.0pt;
  mso-border-alt:solid windowtext .5pt;mso-border-bottom-alt:solid windowtext .25pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:
  "Times New Roman";mso-hansi-font-family:"Times New Roman"'>种别值</span><span
  lang=EN-US style='font-size:12.0pt'>n<o:p></o:p></span></p>
  </td>
  <td width=349 valign=top style='width:261.4pt;border:solid windowtext 1.0pt;
  border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:
  solid windowtext .5pt;mso-border-bottom-alt:solid windowtext .25pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:
  "Times New Roman";mso-hansi-font-family:"Times New Roman"'>取值范围</span><span
  lang=ZH-CN style='font-size:12.0pt'> </span><span lang=EN-US
  style='font-size:12.0pt'>(-2<sup>8n-1</sup></span><span lang=ZH-CN
  style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
  mso-hansi-font-family:"Times New Roman"'>—</span><span lang=EN-US
  style='font-size:12.0pt'>2<sup>8n-1</sup>-1)<o:p></o:p></span></p>
  </td>
  <td width=175 valign=top style='width:131.25pt;border:solid windowtext 1.0pt;
  border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:
  solid windowtext .5pt;mso-border-bottom-alt:solid windowtext .25pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US style='font-size:12.0pt'><o:p>&nbsp;</o:p></span></p>
  </td>
 </tr>
 <tr style='mso-yfti-irow:1'>
  <td width=302 valign=top style='width:226.45pt;border:solid windowtext 1.0pt;
  border-top:none;mso-border-left-alt:solid windowtext .5pt;mso-border-bottom-alt:
  solid windowtext .5pt;mso-border-right-alt:solid windowtext .5pt;padding:
  0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US style='font-size:12.0pt'>INTEGER([KIND=]1) </span><span
  lang=ZH-CN style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
  mso-hansi-font-family:"Times New Roman"'>或</span><span lang=EN-US
  style='font-size:12.0pt'> INTEGER*1 </span></p>
  </td>
  <td width=349 valign=top style='width:261.4pt;border-top:none;border-left:
  none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
  mso-border-left-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;
  mso-border-bottom-alt:solid windowtext .5pt;mso-border-right-alt:solid windowtext .5pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US style='font-size:12.0pt'>-128</span><span lang=ZH-CN
  style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
  mso-hansi-font-family:"Times New Roman"'>—</span><span lang=EN-US
  style='font-size:12.0pt'>127<o:p></o:p></span></p>
  </td>
  <td width=175 valign=top style='width:131.25pt;border-top:none;border-left:
  none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
  mso-border-left-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;
  mso-border-bottom-alt:solid windowtext .5pt;mso-border-right-alt:solid windowtext .5pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US><o:p>&nbsp;</o:p></span></p>
  </td>
 </tr>
 <tr style='mso-yfti-irow:2'>
  <td width=302 valign=top style='width:226.45pt;border:solid windowtext 1.0pt;
  border-top:none;mso-border-top-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;
  padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US style='font-size:12.0pt'>INTEGER([KIND=]2) </span><span
  lang=ZH-CN style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
  mso-hansi-font-family:"Times New Roman"'>或</span><span lang=EN-US
  style='font-size:12.0pt'> INTEGER*2 <o:p></o:p></span></p>
  </td>
  <td width=349 valign=top style='width:261.4pt;border-top:none;border-left:
  none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
  mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;
  mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align:
  none'><span lang=EN-US style='font-size:12.0pt'>-32768</span><span
  lang=ZH-CN style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
  mso-hansi-font-family:"Times New Roman"'>—</span><span lang=EN-US
  style='font-size:12.0pt'>32767<o:p></o:p></span></p>
  </td>
  <td width=175 valign=top style='width:131.25pt;border-top:none;border-left:
  none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
  mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;
  mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt'>
  <p class=MsoNormal align=left style='text-align:left;line-height:15.0pt;
  mso-line-height-rule:exactly;mso-pagination:widow-orphan;mso-layout-grid-align