C***********************??Contents??****************************************
C*?Principal?Components?Analysis:?C?638?lines.?****************************
C*?Sample?input?data?set?（final?36?lines）.?*********************************
C***************************************************************************



/*********************************/
/*?Principal?Components?Analysis?*/
/*********************************/

/*********************************************************************/
/*?Principal?Components?Analysis?or?the?Karhunen-Loeve?expansion?is?a
???classical?method?for?dimensionality?reduction?or?exploratory?data
???analysis.??One?reference?among?many?is:?F.?Murtagh?and?A.?Heck
???Multivariate?Data?Analysis?Kluwer?Academic?Dordrecht?1987.

???Author:
???F.?Murtagh
???Phone:????????+?49?89?32006298?（work）
?????????????????+?49?89?965307?（home）
???Earn/Bitnet:??fionn@dgaeso51??fim@dgaipp1s??murtagh@stsci
???Span:?????????esomc1::fionn
???Internet:?????murtagh@scivax.stsci.edu
???
???F.?Murtagh?Munich?6?June?1989???????????????????????????????????*/???
/*********************************************************************/

#include?
#include?
#include?

#define?SIGN（a?b）?（?（b）?
main（argc?argv）
int?argc;
char?*argv[];

{
FILE?*stream;
int??n?m??i?j?k?k2;
float?**data?**matrix（）?**symmat?**symmat2?*vector（）?*evals?*interm;
void?free_matrix（）?free_vector（）?corcol（）?covcol（）?scpcol（）;
void?tred2（）?tqli（）;
float?in_value;
char?option?*strncpy（）;

/*********************************************************************
???Get?from?command?line:
???input?data?file?name?#rows?#cols?option.

???Open?input?file:?fopen?opens?the?file?whose?name?is?stored?in?the
???pointer?argv[argc-1];?if?unsuccessful?error?message?is?printed?to
???stderr.
*********************************************************************/

???if?（argc?!=??5）
??????{
??????printf（“Syntax?help:?PCA?filename?#rows?#cols?option\n\n“）;
??????printf（“（filename?--?give?full?path?name\n“）;
??????printf（“?#rows??????????????????????????\n“）;
??????printf（“?#cols????--?integer?values\n“）;??????????????????
??????printf（“?option???--?R?（recommended）?for?correlation?analysis\n“）;
??????printf（“?????????????V?for?variance/covariance?analysis\n“）;
??????printf（“?????????????S?for?SSCP?analysis.）\n“）;
??????exit（1）;
??????}

???n?=?atoi（argv[2]）;??????????????/*?#?rows?*/
???m?=?atoi（argv[3]）;??????????????/*?#?columns?*/
???strncpy（&optionargv[4]1）;?????/*?Analysis?option?*/

???printf（“No.?of?rows:?%d?no.?of?columns:?%d.\n“nm）;
???printf（“Input?file:?%s.\n“argv[1]）;

???if?（（stream?=?fopen（argv[1]“r“））?==?NULL）
??????{
??????fprintf（stderr?“Program?%s?:?cannot?open?file?%s\n“
???????????????????????argv[0]?argv[1]）;
??????fprintf（stderr?“Exiting?to?system.“）;
??????exit（1）;
??????/*?Note:?in?versions?of?DOS?prior?to?