function?[dataout?sampint?numsamps?t]?=?segyinput（sgyfile?platform...
????traces?skip?fcode?ucode）

%?function?[dataout?sampint?numsamps?t]?=?segyinput（sgyfile?platform...
%?????traces?skip?fcode?ucode）
%
%?Reads?segy?data?into?a?structured?array?format?in?Matlab?workspace.
%?The?name?of?the?segy?file?and?the?platform?must?both?be?given
%?in?single?quotes.?（Without?single?quotes?you?will?get?an?
%?“????Undefined?variable?‘unquoted?stuff‘.“?error.）
%
%?Segyinput?also?gives?you?the?following?options:?specify?the?number?of?
%?traces?to?read?in?the?format?of?the?data?samples?and?the?units?of?
%?measurement?used?by?the?survey?if?desired.?The?maximum?number?of?traces?
%?that?may?be?read?in?or?skipped?is?approximately?8500?if?each?trace?is?
%?3000?samples?long?and?the?data?is?stored?in?a?4?byte?format.
%
%?Possible?platform?designations?quoted?from?the?FOPEN?Matlab?help?file
%?most?likely?formats?first:
%
%?‘b‘?=?data?written?in?UNIX?format?（big?endian?IEEE?floating?point）
%?‘l‘?=?data?written?in?PC?format?（little?endian?IEEE?floating?point）
%?‘c‘?=?Cray?floating?point?（big?endian）
%?‘s‘?=?64?bit?long?data?type?（big?endian?IEEE?floating?point）
%?‘a‘?=?64?bit?long?data?type?（little?endian?IEEE?floating?point）
%?‘n‘?=?defaults?to?the?format?the?machine?running?Matlab?uses
%?‘d‘?=?VAXD?floating?point?with?VAX?ordering
%?‘g‘?=?VAXG?floating?point?with?VAX?ordering
%
%?dataout???=?a?structured?array?containing?four?fields:?textheader
%?????????????binaryheader?traceheaders?and?data
%?sampint???=?sampling?interval
%?numsamps??=?number?of?samples?per?trace
%?t?????????=?time?vector
%?traces????=?optional?argument?indicates?number?of?traces?to?read?in;
%?????????????otherwise?all?traces?are?read?in?by?default
%?skip??????=?optional?argument;?if?the?number?of?traces?being?read?in?is?
%?????????????specified?this?allows?a?number?of?traces?to?be?skipped?before?
%?????????????the?read?in?begins?（you?may?have?a?trace?setting?without?a
%?????????????skip?setting?but?not?a?skip?setting?without?a?trace?setting）
%?fcode?????=?optional?argument?format?code?for?the?data
%?????????????options?for?fcode?are:
%?????????????1?=?4?byte?floating?point
%?????????????2?=?4?byte?fixed?point
%?????????????3?=?2?byte?fixed?point
%?????????????4?=?fixed?point?with?gain?code?（not?readable?with?this?code）
%?????????????5?=?IBM/360?32-bit?floats
%?ucode?????=?optional?argument?code?for?unit?used?in?the?seismic?survey
%?????????????1?for?metres?2?for?feet
%?
%?Written?by?C.?Osborne?December?2001?Revised?March?2002

%?Check?the?file?name?for?problems.
strlength?=?max（size（sgyfile））;
test1?=?sgyfile（（strlength?-?3）:strlength）;

if?（test1?~=?‘.sgy‘）?|?（test1?~=?‘.seg‘）
????disp（‘?‘）
????disp（‘This?data?does?not?have?a?“.sgy“?or?“.seg“?extension‘）
????disp（‘and?may?not?be?segy?format?data.?Do?you?wish?to?continue?‘）
????intest?=?input（‘Type?y?for?yes?n?for?no?then?hit?the?enter?key.\n‘?‘s‘）
???