谢谢MATLAB 指令窗中的help指令和lookfor指令
c/B'jPt 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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&/Ro lIHF Bo<>e~6P 2.9.2 指令窗中的 help 指令
z4&iK)x i)#s.6.D> 2.9.2.1 直接使用 help 获得指令的使用说明
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y4 Hm+ODv9 【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。
|_omr&[_ p>_;^&>& help logm
G^q3Z#P LOGM Matrix logarithm.
ZeG_en ; 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.
mv5n4mav ?<G]&EK~~] [L,esterr] = logm(A) does not print any warning message, but returns an estimate of the relative residual,norm(expm(L)-A)/norm(A).
B||;' spasB=E If A is real symmetric or complex Hermitian, then so is LOGM(A).
mhW-J6u* o)OUWGjb/K Some matrices, like A = [0 1; 0 0], do not have any logarithms, real or complex, and LOGM cannot be expected to produce one.
aR\\<due %0? M?Jf See also EXPM, SQRTM, FUNM.
a0Ik`8^` O?<&+(uMTT 2.9.2.2 使用 help 指令进行分类搜索
qc#)! VUI|.76g 【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。
8k(P,o vD 5vbl help
)sho*;_o HELP topics:
9;?UvOI; matlab\general - General purpose commands.
k</%YKk matlab\ops - Operators and special characters.
{EdH$l>94 matlab\lang - Programming language constructs.
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"Q/ matlab\elmat - Elementary matrices and matrix manipulation.
#2`D`>7456 matlab\elfun - Elementary math functions.
*D'$"@w3 matlab\specfun - Specialized math functions.
='TE,et@d ...... ......
y^]tahbo For more help on directory/topic, type "help topic".
c1%H4j4/ >DPB!XA3 2.9.2.3 采用 help topic 指令形式获得具体子类的指令明细
lV.F,3 ho>k$s? 【例 2.9.2 .3-1 】如果用户想知道有关矩阵操作指令一栏表,那末就运行以下指令。
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-Ij& help elmat
Xn~I=Ml d Elementary matrices and matrix manipulation.
O@?kT;B Elementary matrices.
LN_xq&. zeros - Zeros array.
7Sz?S_N/j ones - Ones array.
~tOAT;g}q ...... ......
PvGDTYcKp QXF
aAb=(7 Basic array information.
P>9aI/d9 size - Size of matrix.
1 { , F length - Length of vector.
8EVgoJ. ...... ......
Fq9Q+RNMZL lY*[tmz) Matrix manipulation.
*m2=/Sh reshape - Change size.
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*1{6g diag - Diagonal matrices and diagonals of matrix.
"bDs2E+W ...... ......
0(_l|PScF `GXkF:f= Special variables and constants.
YDGS}~m~Q ans - Most recent answer.
H5D*|42 eps - Floating point relative accuracy.
yjJ5P`j] ...... ......
<L&m4O#| .(Qx{r$ Specialized matrices.
waKT{5k compan - Companion matrix.
aTf`BG{kw gallery - Higham test matrices.
"T H6o:x ...... ......
+nQw?'9Z v:+~9w+ 〖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。
)]#aa uC+ G<M:Ak+~ fvb=#58N_ 2.9.3 指令窗中的 lookfor 指令
tl'n->G>v 1".v6caW 【例 2.9.3 -1 】查找包含积分这个关键词的所有指令。
r=c<--_@ 0-{tFN lookfor integral
h5yzwj:C? ELLIPKE Complete elliptic integral.
$ cu00K EXPINT Exponential integral function.
A{B/lX) DBLQUAD Numerically evaluate double integral.
ki>~H!zB INNERLP Used with DBLQUAD to evaluate inner loop of integral.
(MHAJ]Rx QUAD Numerically evaluate integral, low order method.
y,pZTlE QUAD8 Numerically evaluate integral, higher order method.
MQKfJru7 COSINT Cosine integral function.
x1 1U@jd+1 SININT Sine integral function.
["}rk ASSEMA Assembles area integral contributions in a PDE problem.
T)\"Xj COSINT Cosine integral function.
r\;ut4wy FOURIER Fourier integral transform.
M@W[Bz IFOURIER Inverse Fourier integral transform.
l|5fE1K9U SININT Sine integral function.