%%%%?the?program?is?to?compute?the?parameter?of?PEER?Ground?Motion
clear
clc
close?all
filename=dir（‘D:\matlab_my_data\work_for_liangyan‘）;
n=length（filename）;
%=========?the?Names?of?items?which?we?want?to?get?============%
File_Name=cell（n1）;PGA=zeros（n1）;PGV=zeros（n1）;PGD=zeros（n1）;
Uniform_Dur=zeros（n1）;Bracketed_Dur=zeros（n1）;D90=zeros（n1）;
AI=zeros（n1）;MIV=zeros（n1）;MID=zeros（n1）;CAV=zeros（n1）;CAVSTD=zeros（n1）;
SA_02=zeros（n1）;SA_1=zeros（n1）;SV_02=zeros（n1）;SV_1=zeros（n1）;SD_02=zeros（n1）;
SD_1=zeros（n1）;EPA=zeros（n1）;EPV=zeros（n1）;VSI=zeros（n1）;
g=980;
%=======================================================================%
for?k=1:n
????%===========?read?the?namelist?of?files?=======================%
????ss=length（filename（k）.name）;
????File_Name{k}=filename（k）.name（1:ss-4）;
????%?to?read?the?kth?file
????[InforAcceleration]=Read_Files_Peer（[‘over50\‘filename（k）.name]）;
????Dt=Infor.Dt;
????Acceleration=Acceleration*g;?%?the?unit?of?acceleration?is?gal
????count=length（Acceleration）;
????Velocity=zeros（count1）;
????Displacement=zeros（count1）;
????%============?COMPUTE?PGA??PGV?and?PGD?========================%
????PGA（k）=max（abs（Acceleration））;
????for?ii=1:（count-1）
????????Velocity（ii+1）=Velocity（ii）+（Acceleration（ii）+Acceleration（ii+1））*Dt*（1/2）;
????????Displacement（ii+1）=Displacement（ii）+Velocity（ii）*Dt+（Acceleration（ii）*（1/3）+Acceleration（ii+1）*（1/6））*Dt*Dt;
????end
????PGV（k）=max（abs（Velocity））;
????PGD（k）=max（abs（Displacement））;
????%==============??COMPUTE?Uniform?Duration?:?Uniform_Dur?===============%
????Default1=0.05*PGA（k）;
????n1=0;
????for?k1=1:count
????????if?abs（Acceleration（k1））>Default1
????????????n1=n1+1;
????????end
????end
????Uniform_Dur（k）=n1*Dt;
????%===========?COMPUTE?Bracketed?Duration?:?Bracketed_Dur?===============%
????Default2=Default1;
????C=find（abs（Acceleration）>Default2）;
????BT1=max（C）;
????BT2=min（C）;
????Bracketed_Dur（k）=（BT1-BT2+1）*Dt;
????%===============?COMPUTE?Significant?Duration?:?D90=============%
????IT=0;
????for?k2=1:count-1
????????IT=IT+（Acceleration（k2）*Acceleration（k2）+Acceleration（k2+1）*Acceleration（k2+1））*Dt*（1/2）;
????end
????ITt=0;
????for?k3=1:count-1
????????ITt=ITt+（Acceleration（k3）*Acceleration（k3）+Acceleration（k3+1）*Acceleration（k3+1））*Dt*（1/2）;
????????if?ITt>0.05*IT
????????????t1=（k3-1）*Dt;
????????????break;
????????end
????end
????for?k4=1:count-1
????????ITt=ITt+（Acceleration（k4）*Acceleration（k4）+Acceleration（k4+1）*Acceleration（k4+1））*Dt*（1/2）;
????????if?ITt>0.95*IT
????????????t2=（k4-1）*Dt;
????????????break;
????????end
????end
????D90（k）=t2-t1;
????%============?COMPUTE?Arias?Intensity?:?AI?=======================%
????AI（k）=IT*pi/（2*g）;
????%=?COMPUTE?Maximum?Increment?Velocity?and?Displacement?:?MIV?and?MID?=%
????IV=zeros（count1）;ID=zeros（count1）;
????j=1;jj=1;k5=1;
????while?j+k5<=count
????????if?Acceleration（j）*Acceleration（j+k5）>0
????????????k5=k5+1;
??