?? matlib hand book in chinese.htm
字號:
norm(x): </span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>的欧氏（</span><span
lang=EN-US>Euclidean</span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）长度</span><span
lang=EN-US> <br>
sum(x): </span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>的元素总和</span><span
lang=EN-US> <br>
prod(x): </span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>的元素总乘积</span><span
lang=EN-US> <br>
cumsum(x): </span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>的累计元素总和</span><span
lang=EN-US> <br>
cumprod(x): </span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>的累计元素总乘积</span><span
lang=EN-US> <br>
dot(x, y): </span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>和</span><span lang=EN-US>y</span><span
style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>的内积</span><span lang=EN-US> <br>
cross(x, y): </span><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>向量</span><span
lang=EN-US>x</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>和</span><span lang=EN-US>y</span><span
style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>的外积（大部份的向量函数也可适<span
class=GramE>用於</span>矩阵，详见下述。）</span><span
lang=EN-US> <br>
<br>
<br>
</span><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>若要输入矩阵，则必须在每一列结尾加上分号（；），如下例：</span><span
lang=EN-US> <br>
<br>
<br>
A = [1 2 3 4; 5 6 7 8; 9 10 11 12];
<br>
<br>
A <br>
<br>
A = <br>
<br>
1 2 3 4 <br>
<br>
5 6 7 8 <br>
<br>
9 10 11 12 <br>
<br>
<br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>同样地，我们可以对矩阵进行各种处理：</span>
</span><span lang=EN-US><br>
<br>
<br>
<span class=content>A(2,3) = 5 % </span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>改变位<span
class=GramE>於</span>第二列，第三行的元素值</span><span
lang=EN-US> </span></span><span lang=EN-US><br>
<br>
<span class=content>A = </span><br>
<br>
<span class=content>1 2 3 4 </span><br>
<br>
<span class=content>5 6 5 8 </span><br>
<br>
<span class=content>9 10 11 12 </span><br>
<br>
<br>
<span class=content>B = A(2,1:3) % </span></span><span
class=GramE><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>取出部</span></span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>份矩阵</span><span
lang=EN-US>B </span></span><span lang=EN-US><br>
<br>
<span class=content>B = </span><br>
<br>
<span class=content>5 6 5 </span><br>
<br>
<br>
<span class=content>A = [A B'] % </span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>将</span><span lang=EN-US>B</span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>转置<span class=GramE>後</span>以行向量并入</span><span
lang=EN-US>A </span></span><span lang=EN-US><br>
<br>
<span class=content>A = </span><br>
<br>
<span class=content>1 2 3 4 5 </span><br>
<br>
<span class=content>5 6 5 8 6 </span><br>
<br>
<span class=content>9 10 11 12 5 </span><br>
<br>
<br>
<span class=content>A(:, 2) = [] % </span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>删除第二行（：代表所有列）</span><span
lang=EN-US> </span></span><span lang=EN-US><br>
<br>
<span class=content>A = </span><br>
<br>
<span class=content>1 3 4 5 </span><br>
<br>
<span class=content>5 5 8 6 </span><br>
<br>
<span class=content>9 11 12 5 </span><br>
<br>
<br>
<span class=content>A = [A; 4 3 2 1] % </span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>加入第四列</span><span
lang=EN-US> </span></span><span lang=EN-US><br>
<br>
<span class=content>A = </span><br>
<br>
<span class=content>1 3 4 5 </span><br>
<br>
<span class=content>5 5 8 6 </span><br>
<br>
<span class=content>9 11 12 5 </span><br>
<br>
<span class=content>4 3 2 1 </span><br>
<br>
<br>
<span class=content>A([1 4], :) = [] % </span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>删除第一和第四列（：代表所有行）</span><span
lang=EN-US> <span style='mso-tab-count:3'>牋牋牋牋牋牋牋牋牋 </span><gdptag
matlib tech</span></span><span class=content><span style='font-family:SimSun;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>删除行列</span>
<span lang=EN-US>></span></span><span lang=EN-US><br>
<br>
<span class=content>A = </span><br>
<br>
<span class=content>5 5 8 6 </span><br>
<br>
<span class=content>9 11 12 5 </span><br>
<br>
<br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>这几种矩阵处理的方式可以<span
class=GramE>相互叠代运用</span>，产生各种意想不到的效果，就看各位的巧思和</span></span><span
lang=EN-US><br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>创意。</span></span><span
lang=EN-US><br>
<span class=content> </span><br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>小提示：</span><span
lang=EN-US> </span></span><span class=content><span style='font-family:
SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>在</span><span
lang=EN-US>MATLAB</span></span><span class=content><span style='font-family:
SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>的内部资料结构中，每一个矩阵都是一个以行为主（</span><span
lang=EN-US>Column-oriented</span></span><span lang=EN-US><br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）的阵列（</span><span
lang=EN-US>Array</span></span><span class=content><span style='font-family:
SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）因此对<span
class=GramE>於</span>矩阵元素的存取，我们可用一维或二维的索引（</span><span
lang=EN-US>Index</span></span><span class=content><span style='font-family:
SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）来定</span></span><span
lang=EN-US><br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>址。举例来说，在上述矩阵</span><span
lang=EN-US>A</span></span><span class=content><span style='font-family:SimSun;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>中，位<span
class=GramE>於</span>第二列、第三行的元素可写为</span><span
lang=EN-US>A(2,3) </span></span><span class=content><span
style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>（二维索引）</span></span><span
lang=EN-US><br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>或</span><span
lang=EN-US>A(6)</span></span><span class=content><span style='font-family:SimSun;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>（一维索引，即将所有直行进行堆叠<span
class=GramE>後</span>的第六个元素）。</span><span
lang=EN-US> </span></span><span lang=EN-US><br>
<br>
</span><span class=content><span style='font-family:SimSun;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>此外，若要重新安排矩阵的形状，可用</span><span
lang=EN-US>reshape</span></span><span class=content><span style='font-family:
SimSun;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>命令：</span><span
lang=EN-US> </span></span><span lang=EN-US><br>
<br>
<span class=content>B = reshape(A, 4, 2) % 4</span></span><span
class=content><span style='font-family:SimSun;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>是新矩阵的列数，</span><span
lang=EN-US>2</span></span><span class=content><span style='font-?? 快捷鍵說明
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