📄 第六节 mathematica编程基础.htm
字号:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>第六节 Mathematica编程基础</title>
</head>
<body bgcolor="#00FFFF">
<P align=center class=MsoNormal style="text-align: center; line-height: 200%"><span style="font-family: 宋体; mso-hansi-font-family: Times New Roman; mso-ascii-font-family: Times New Roman"><a href="index.htm">主目录</a></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">
| <a href="第二节%20用Mathematica求极限和求微分.htm"></a> <a href="第一节%20Mathematica快速入门.htm">第一节</a>
| <a href="第二节%20用Mathematica求极限和求微分.htm">第二节</a> | <a href="第三节%20用Mathematica作积分计算.htm">第三节</a>
| <a href="第四节%20用Mathematica解方程和作级数运算.htm">第四节</a>
| <a href="第五节%20用Mathematica进行向量运算和作图.htm">第五节</a>
| <a href="第六节%20Mathematica编程基础.htm">第六节</a></span></P>
<P align=center class=MsoNormal style="text-align: center; line-height: 200%"> </P>
<P align=center class=MsoNormal style="text-align: center; line-height: 200%"><font color="#FF0000" size="6"><b><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">第六节</SPAN><SPAN
lang=EN-US> Mathematica</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">编程基础</SPAN></b></font></P>
<P class=MsoNormal style="text-indent: 17.95pt; line-height: 200%"><font size="4"><b><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">在以前我们所讲的章节里，我们执行的命令一般是一句一句操作的。显然对于工程中一个比较复杂的运算，这样的操作要费一番周折。特别是在运算过程中往往需要进行逻辑判断，所以常常需要写成一段连续的代码，这样在运行时会更加方便。使用</SPAN><SPAN
lang=EN-US>Mathematica</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">编程可以更加有效地实现复杂的操作。编写程序实际上就是定义表达式地变换规则，在使用</SPAN><SPAN
lang=EN-US>Mathematica</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">进行运算时实际上也就是写表达式。这些表达时按功能可以分为两类：一类用与描述计算机要执行的操作运算（如赋值运算），称为操作运算语句，另一类是控制上述操作运算的执行顺序（如循环控制语句），也就是流程控制语句。本节着中阐述流程控制语句。在讲述流程控制语句之前，我们先看一看计算机是如何判定一个表达时是否成立的（逻辑运算）。</SPAN></b></font></P>
<P class=MsoNormal style="line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'"><b><font color="#FF0000" size="5">一、<a name="逻辑运算">逻辑运算</a></font></b></SPAN></P>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN lang=EN-US
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>Mathematica的逻辑运算结果有两种：True（真、成立）和False（假、不成立）。逻辑运算符如下：<O:P>
</O:P></b></font></SPAN></P>
<TABLE border=1 cellPadding=0 cellSpacing=0
style="BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse; BORDER-LEFT: medium none; BORDER-RIGHT: medium none; BORDER-TOP: medium none; mso-table-layout-alt: fixed; mso-border-alt: solid windowtext .75pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt">
<TBODY>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: windowtext 0.75pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>表示符号<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: windowtext 0.75pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>含义<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD></TR>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
lang=EN-US
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>lhs==rhs
或SameQ[lhs,rhs]<O:P> </O:P></b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>当两边的表达式相等时成立（结果为真）<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD></TR>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
lang=EN-US
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>Lhs!=rhs
或UnSameQ[lhs,rhs]<O:P> </O:P></b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>当两边的表达式不等时结果为真<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD></TR>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
lang=EN-US
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>Expr1&&expr2&&expr3<O:P>
</O:P></b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>各表达式都成立时为真<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD></TR>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
lang=EN-US
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>Expr1||expr2||expr3<O:P>
</O:P></b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P align=left class=MsoNormal
style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><font size="4"><b>至少有一个表达时成立时为真<SPAN
lang=EN-US><O:P> </O:P></SPAN></b></font></SPAN></P></TD></TR>
<TR>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: windowtext 0.75pt solid; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
<P class=MsoNormal style="text-indent: 17.95pt; mso-list: skip; line-height: 200%"><SPAN
lang=EN-US><font size="4"><b>TrueQ[expr]</b></font></SPAN></P></TD>
<TD
style="BORDER-BOTTOM: windowtext 0.75pt solid; BORDER-LEFT: medium none; BORDER-RIGHT: windowtext 0.75pt solid; BORDER-TOP: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; PADDING-RIGHT: 5.4pt; PADDING-TOP: 0cm; WIDTH: 213.05pt; mso-border-left-alt: solid windowtext .75pt; mso-border-top-alt: solid windowtext .75pt"
vAlign=top width=284>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -