function?[vp1freqvp2vsq1invq2invqsinv]=biot（vpdryvsdryk0mu0ro0roflkflnuporpermaalfad1d2opt）
%[VP1FREQVP2VSQ1INVQ2INVQSINV]
%??????=BIOT（VPDRYVSDRYK0MU0RO0ROFLKFLNUPORPERMAALFAD1D2‘PLOTOPT‘）
%
%	calculates?the?complete?Biot?velocity?dispersion?and?attenuation
%	curves?for?all?frequencies.?
%?Inputs:?VPDRY:?P-wave?velocity?of?dry?porous?rock
%	??VSDRY:?S-wave?velocity?of?dry?porous?rock
%	??K0?MU0?RO0:??Mineral?Bulk?modulus?shear?modulus?and?density
%	??ROFLKFLNU:?Pore?fluid?density?bulk?modulus?and?viscosity
%	??POR?PERM:?Porosity?and?absolute?permeability?of?porous?rock
%	??A:?pore?size?parameter;?usually?about?1/6-1/7?of?grain?diameter
%	??ALFA:?Tortuosity?parameter?（always?>?1）?usually?between?1-3
%	??D1D2:?frequency?range?from?10^D1?to?10^D2
%	??‘PLOTOPT‘:?optional?input?for?plotting.?If?nothing?is?given?plots?of
%	??all?six?outputs?versus?frequency?are?displayed.?The?following?options
%	??selects?only?one?of?the?outputs?for?plotting.
%	??‘PLOTOPT‘=‘VP1‘?displays?VP1?（fast?P-wave）?dispersion?curve
%		???=‘VP2‘?displays?VP2?（slow?P-wave）?dispersion?curve
%		???=‘VS‘??displays?VS?（shear?wave）?dispersion?curve
%		???=‘QP1‘?displays?P1?attenuation?curve
%		???=‘QP2‘?displays?P2?attenuation?curve
%		???=‘QS‘??displays?S?attenuation?curve
%?Outputs:?VP1:?Fast?P-wave?velocities?at?all?frequencies
%	???FREQ:?Frequencies?at?which?velocity?and?attenuation?are?calculated
%	???VP2:?Slow?P-wave?velocities?at?all?frequencies
%	???VS:??S-wave?velocities
%	???Q1INV?Q2INV?QSINV:?Fast?and?slow?P-wave?and?S-wave?attenuations
%
%	???See?also?BIOTHF?BIOTHFB

%?Written?by?T.?Mukerji?1996

if?nargin<15?%?nargin??是matlab的內(nèi)置函數(shù)，返回值為函數(shù)的輸入?yún)?shù)的個(gè)數(shù)；
????opt=‘a(chǎn)ll6‘;?
end;?
ro=（1-por）*ro0+por*rofl;%平均法計(jì)算飽和巖石的密度；
rodry=（1-por）*ro0;?%計(jì)算干巖心的密度；
omc=por*nu/（rofl*perm）;%?計(jì)算臨界角頻率；
mudry=rodry.*vsdry.^2;?%?利用Vs_dry計(jì)算干巖心（骨架）的剪切模量；
kdry=rodry.*vpdry.^2-（4/3）*mudry;?%利用Vp_dry計(jì)算干巖心（骨架）的體積模量；
d=k0*（1+por*（k0/kfl-1））;?%?計(jì)算參數(shù)D，表達(dá)式見Handbook中P140；
h=kdry+（4/3）*mudry+（k0-kdry）.^2./（d-kdry）;?%?計(jì)算參數(shù)H;
c=k0*（k0-kdry）./（d-kdry）;?%計(jì)算參數(shù)C；
m=k0.^2./（d-kdry）;?%計(jì)算參數(shù)M；
%從第47行到第58行都是為了計(jì)算q;
freq=logspace（d1d2100）;?%?在[0^d1，10^d2]之間等對(duì)數(shù)間距的產(chǎn)生100個(gè)數(shù)據(jù)點(diǎn)，返回值為行向量，1*100；
om=2*pi*freq;?%計(jì)算角頻率om為行向量，長(zhǎng)度為100;
zeta=sqrt（（rofl*a^2/nu）*om）;%計(jì)算中間參數(shù)Zeta，為行向量，1*100;
t=zeros（size（zeta））;?%設(shè)置零矩陣，1*100；
idx=[zeta?<=?1e3];%?idx與Zeta具有相同的長(zhǎng)度，如果Zeta（j）<=1e3則idx（j）=1;反之，idx（k）=0;
idxl=[zeta?<=?1e-1];
t（idx）=exp（i*3*pi/4）*bessel（1exp（-i*pi/4）*zeta（idx））./...
????????bessel（0exp（-i*pi/4）*zeta（idx））;
t（~idx）=（（1+i）/sqrt（2））*ones（sum（~idx）1）;
f=0.25*zeta.*t./（1+i*2*t./zeta）;?%?計(jì)算參數(shù)F（Zeta）
f（idxl）=ones（sum（idxl）1）;
qf=alfa*rofl/por?-?（i*nu/perm）*f./om;%?計(jì)算參數(shù)q;
%%%%%%%%%%%%test?of?qf
%qf=alfa*rofl/por?+?（i*nu/perm）*f./om;?this?equation?is?wrong;?sign?is?-
%%%%%%%%%%%

b0=rofl^2-ro*qf;
b1=h*qf+m*ro-2*c*rofl;
b2=c^2-m*h;?%b0b1b2為求解Vp時(shí)用的參數(shù)；
sl1sqr=（-b1+sqrt（b1.^2-4*b2*b0））./（2*b2）;
sl2sqr=（-b1-sqrt（b1.^2-4*b2*b0））./（2*b2）;
slssqr=（ro*qf-rofl^2）./（mudry*qf）;
vp1=1./real（sqrt（s

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2013-07-02?15:43??biot?雙向介質(zhì)正演模擬matlab程序\
?????文件?????2221462??2013-04-23?18:01??biot?雙向介質(zhì)正演模擬matlab程序\250ms_snapshotz_f.dat
?????文件?????2220020??2013-04-23?18:01??biot?雙向介質(zhì)正演模擬matlab程序\250ms_snapshotz_s.dat
?????文件????????4104??2011-09-29?17:15??biot?雙向介質(zhì)正演模擬matlab程序\biot.m
?????文件???????10278??2011-12-22?16:01??biot?雙向介質(zhì)正演模擬matlab程序\biot_2_4_PML.m
?????文件????13860613??2013-04-23?18:01??biot?雙向介質(zhì)正演模擬matlab程序\offset_vx_s
?????文件????13860613??2013-04-23?18:02??biot?雙向介質(zhì)正演模擬matlab程序\offset_vz_s