谢谢MATLAB 指令窗中的help指令和lookfor指令
ti9}*8 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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%?=)!;[ c<jB6|.=2 2.9.2 指令窗中的 help 指令
+)gB9DoK KlO(o#&N 2.9.2.1 直接使用 help 获得指令的使用说明
v8'5pLt" %wL,v.} 【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。
:-Wv>V\t c#pj :f*H help logm
TB#Nk5 LOGM Matrix logarithm.
3dm'xetM 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.
KY+]RxX mHs:t{q [L,esterr] = logm(A) does not print any warning message, but returns an estimate of the relative residual,norm(expm(L)-A)/norm(A).
j-32S! hk;bk?:m If A is real symmetric or complex Hermitian, then so is LOGM(A).
ym%o}(v- gp/YjUH7k8 Some matrices, like A = [0 1; 0 0], do not have any logarithms, real or complex, and LOGM cannot be expected to produce one.
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,mleM See also EXPM, SQRTM, FUNM.
~6d5zI4\ ;BVDt 2.9.2.2 使用 help 指令进行分类搜索
!<r8~A3!( ML=z<u+ 【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。
,sI35I J (}~ucI<~ help
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#7 HELP topics:
61:9(*4~!F matlab\general - General purpose commands.
hdj%|~Fj matlab\ops - Operators and special characters.
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o+ ? matlab\lang - Programming language constructs.
sX'nn matlab\elmat - Elementary matrices and matrix manipulation.
g1V)$s7 matlab\elfun - Elementary math functions.
sHs g_6~ matlab\specfun - Specialized math functions.
xb`CdtG2. ...... ......
j38 6gL For more help on directory/topic, type "help topic".
xA-jvu9@ \ V?I+Gc 2.9.2.3 采用 help topic 指令形式获得具体子类的指令明细
xJc.pvVPw X6kaL3L} 【例 2.9.2 .3-1 】如果用户想知道有关矩阵操作指令一栏表,那末就运行以下指令。
@p]UvqtB@ oHsP?%U help elmat
}]GbUC!Zb Elementary matrices and matrix manipulation.
Efr3x{ j Elementary matrices.
B5`;MQJ zeros - Zeros array.
Hirr=a3 ones - Ones array.
3:AU: ...... ......
|j#
^@R **HrWM%?8o Basic array information.
~`[8"YUL size - Size of matrix.
!gJzg*{u@ length - Length of vector.
BS.= ...... ......
H:MUNc8i +{*)}[w{x Matrix manipulation.
I>hmbBlDv reshape - Change size.
/.@x
4cdS diag - Diagonal matrices and diagonals of matrix.
zq=&4afOE ...... ......
UN(3i(d 5M.Red.L Special variables and constants.
ay-9c2E ans - Most recent answer.
xT=ySa$|> eps - Floating point relative accuracy.
vv*
|F ...... ......
|*1xrM:v~ )f[C[Rd Specialized matrices.
D-D# ` compan - Companion matrix.
K1-+A2snhV gallery - Higham test matrices.
WL/5 oj ...... ......
z}3di5+P wt\m+!u` 〖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。
NfqJ=9 !mae^A1 ]CIe~q 2.9.3 指令窗中的 lookfor 指令
MYu`c[$jZ S*s:4uf 【例 2.9.3 -1 】查找包含积分这个关键词的所有指令。
4znH$M>bU )*W=GY* lookfor integral
AHWh}~Yi ELLIPKE Complete elliptic integral.
TH>,v EXPINT Exponential integral function.
Lz?*B$h DBLQUAD Numerically evaluate double integral.
HoL~j( { INNERLP Used with DBLQUAD to evaluate inner loop of integral.
<OIUyZS QUAD Numerically evaluate integral, low order method.
BPh".R J QUAD8 Numerically evaluate integral, higher order method.
qL,ka COSINT Cosine integral function.
ETxp#PZ SININT Sine integral function.
`ReGnT[ ASSEMA Assembles area integral contributions in a PDE problem.
3jXR"@Z- COSINT Cosine integral function.
Xout:dn FOURIER Fourier integral transform.
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$%G IFOURIER Inverse Fourier integral transform.
S7Znz@ SININT Sine integral function.