谢谢MATLAB 指令窗中的help指令和lookfor指令
^|MS2' 作者:精通MATLAB(5.3版) 来源:转载
http://www.51base.com/machine/softedu/cam/matlab/5120060126150.shtml 发布时间:2008-4-16 9:29:54
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.JKH=?~\ +'m9b7+v 2.9.2 指令窗中的 help 指令
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q.8~Z 2.9.2.1 直接使用 help 获得指令的使用说明
bhUE!h< r%;|gIky 【例 2.9.2 .1-1 】假如准确知道所要求助的主题词,或指令名称,那末使用 help 是获得在线帮助的最简单有效的途径。本例演示:关于矩阵对数函数 logm 使用说明的在线求助。
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zg(C} help logm
gxO~44" LOGM Matrix logarithm.
]C^ #)7 L = LOGM(A) is the matrix logarithm of A, the inverse of EXPM(A). Complex results are produced if A has negative eigenvalues. A warning message is printed if the computed expm(L) is not close to A.
h!wq&Vi4 cpk\;1&t [L,esterr] = logm(A) does not print any warning message, but returns an estimate of the relative residual,norm(expm(L)-A)/norm(A).
. gy:Pl]w W<q<}RSn If A is real symmetric or complex Hermitian, then so is LOGM(A).
sO) H#G yq.@-]ytZ Some matrices, like A = [0 1; 0 0], do not have any logarithms, real or complex, and LOGM cannot be expected to produce one.
+^9^)Ur| +j: &_ See also EXPM, SQRTM, FUNM.
:0@0muo Sv#MlS> 2.9.2.2 使用 help 指令进行分类搜索
&~eCDlX/ ]ttF''lH 【例 2.9.2 .2-1 】运行不带任何限定的 help ,可以得到分类名称明细表。
\8#[AD*@s2 gbMA-r:IC help
{U-z(0 HELP topics:
w#1BHx matlab\general - General purpose commands.
N%Bl+7,q matlab\ops - Operators and special characters.
~Y43`@3H: matlab\lang - Programming language constructs.
6KGT?d matlab\elmat - Elementary matrices and matrix manipulation.
$x }R2 matlab\elfun - Elementary math functions.
oJM;CN matlab\specfun - Specialized math functions.
PZ/tkw ...... ......
T
?Om]:j For more help on directory/topic, type "help topic".
2l,>x 3F,M{'q 2.9.2.3 采用 help topic 指令形式获得具体子类的指令明细
6c+29@ 3q4VH q 【例 2.9.2 .3-1 】如果用户想知道有关矩阵操作指令一栏表,那末就运行以下指令。
ot7f?tF2<J D;JZ0." help elmat
iAe"oXK| Elementary matrices and matrix manipulation.
zji9\ Elementary matrices.
Hva!6vwO%O zeros - Zeros array.
Yjo$vQi ones - Ones array.
YAR$6& ...... ......
#_\**%,< ();Z,A Basic array information.
#U0| j?!D size - Size of matrix.
pKXSJ"Xo length - Length of vector.
7r,GdP . ...... ......
8]&Fu3M^ ],AtR1k Matrix manipulation.
&H+ wzx< reshape - Change size.
Z^]Oic/0Oa diag - Diagonal matrices and diagonals of matrix.
H5]q*D2 ...... ......
euY+jc% !rgXB( Special variables and constants.
`Zp*? ans - Most recent answer.
\Uh/(q7 eps - Floating point relative accuracy.
=?L16mu1& ...... ......
MuO(%.H Qv,ORm
h5 Specialized matrices.
FXk*zXn6 compan - Companion matrix.
Y<^Or gallery - Higham test matrices.
8F\'?7 ...... ......
VB^1wm gT[] "ZT7 〖说明〗省略号由笔者所加,用来表示被删除的内容。这样做是出于节省篇幅的考虑。
DB"z93Mr<K =Q;dYx%I5 zKk=R6w 2.9.3 指令窗中的 lookfor 指令
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N@ 【例 2.9.3 -1 】查找包含积分这个关键词的所有指令。
s'/_0 -=
c&K& lookfor integral
0XE6Hw ELLIPKE Complete elliptic integral.
X$%[%q8qg EXPINT Exponential integral function.
XwIHIG} DBLQUAD Numerically evaluate double integral.
\xOYa INNERLP Used with DBLQUAD to evaluate inner loop of integral.
;|= 5)KE QUAD Numerically evaluate integral, low order method.
/"!ck2d&1 QUAD8 Numerically evaluate integral, higher order method.
Cjt].XR@ COSINT Cosine integral function.
-iy17$ SININT Sine integral function.
?/3{gOgI$` ASSEMA Assembles area integral contributions in a PDE problem.
|p/[sD+M COSINT Cosine integral function.
q%s<y+ FOURIER Fourier integral transform.
DbI)tDi5D IFOURIER Inverse Fourier integral transform.
JWM4S4yZHR SININT Sine integral function.