--- imach/src/imach.c	2023/05/23 12:08:43	1.356
+++ imach/src/imach.c	2023/06/14 14:55:52	1.357
@@ -1,6 +1,9 @@
-/* $Id: imach.c,v 1.356 2023/05/23 12:08:43 brouard Exp $
+/* $Id: imach.c,v 1.357 2023/06/14 14:55:52 brouard Exp $
   $State: Exp $
   $Log: imach.c,v $
+  Revision 1.357  2023/06/14 14:55:52  brouard
+  * imach.c (Module): Testing if conjugate gradient could be quicker when lot of variables POWELLORIGINCONJUGATE
+
   Revision 1.356  2023/05/23 12:08:43  brouard
   Summary: 0.99r46
 
@@ -1292,6 +1295,7 @@ Important routines
 /* #define POWELLORIGINAL /\* Don't use Directest to decide new direction but original Powell test *\/ */
 /* #define MNBRAKORIGINAL /\* Don't use mnbrak fix *\/ */
 /* #define FLATSUP  *//* Suppresses directions where likelihood is flat */
+#define POWELLORIGINCONJUGATE  /* Don't use conjugate but biggest decrease if valuable */
 
 #include <math.h>
 #include <stdio.h>
@@ -1384,12 +1388,12 @@ double gnuplotversion=GNUPLOTVERSION;
 #define ODIRSEPARATOR '\\'
 #endif
 
-/* $Id: imach.c,v 1.356 2023/05/23 12:08:43 brouard Exp $ */
+/* $Id: imach.c,v 1.357 2023/06/14 14:55:52 brouard Exp $ */
 /* $State: Exp $ */
 #include "version.h"
 char version[]=__IMACH_VERSION__;
 char copyright[]="April 2023,INED-EUROREVES-Institut de longevite-Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research 25293121), Intel Software 2015-2020, Nihon University 2021-202, INED 2000-2022";
-char fullversion[]="$Revision: 1.356 $ $Date: 2023/05/23 12:08:43 $"; 
+char fullversion[]="$Revision: 1.357 $ $Date: 2023/06/14 14:55:52 $"; 
 char strstart[80];
 char optionfilext[10], optionfilefiname[FILENAMELENGTH];
 int erreur=0, nberr=0, nbwarn=0; /* Error number, number of errors number of warnings  */
@@ -2755,7 +2759,9 @@ void powell(double p[], double **xi, int
       printf("%d",i);fflush(stdout); /* print direction (parameter) i */
       fprintf(ficlog,"%d",i);fflush(ficlog);
 #ifdef LINMINORIGINAL
-      linmin(p,xit,n,fret,func); /* Point p[n]. xit[n] has been loaded for direction i as input.*/
+      linmin(p,xit,n,fret,func); /* New point i minimizing in direction i has coordinates p[j].*/
+      /* xit[j] gives the n coordinates of direction i as input.*/
+      /* *fret gives the maximum value on direction xit */
 #else
       linmin(p,xit,n,fret,func,&flat); /* Point p[n]. xit[n] has been loaded for direction i as input.*/
 			flatdir[i]=flat; /* Function is vanishing in that direction i */
@@ -2785,9 +2791,8 @@ void powell(double p[], double **xi, int
       fprintf(ficlog,"\n");
 #endif
     } /* end loop on each direction i */
-    /* Convergence test will use last linmin estimation (fret) and compare former iteration (fp) */ 
+    /* Convergence test will use last linmin estimation (fret) and compare to former iteration (fp) */ 
     /* But p and xit have been updated at the end of linmin, *fret corresponds to new p, xit  */
-    /* New value of last point Pn is not computed, P(n-1) */
     for(j=1;j<=n;j++) {
       if(flatdir[j] >0){
         printf(" p(%d)=%lf flat=%d ",j,p[j],flatdir[j]);
@@ -2925,10 +2930,17 @@ void powell(double p[], double **xi, int
 	  }
 	}
 #endif
+#ifdef POWELLORIGINCONJUGATE
 	for (j=1;j<=n;j++) { 
 	  xi[j][ibig]=xi[j][n]; /* Replace direction with biggest decrease by last direction n */
 	  xi[j][n]=xit[j];      /* and this nth direction by the by the average p_0 p_n */
 	}
+#else
+	for (j=1;j<=n-1;j++) { 
+	  xi[j][1]=xi[j][j+1]; /* Standard method of conjugate directions */
+	  xi[j][n]=xit[j];      /* and this nth direction by the by the average p_0 p_n */
+	}
+#endif
 #ifdef LINMINORIGINAL
 #else
 	for (j=1, flatd=0;j<=n;j++) {
@@ -2957,6 +2969,15 @@ void powell(double p[], double **xi, int
 #endif
 	printf("Gaining to use new average direction of P0 P%d instead of biggest increase direction %d :\n",n,ibig);
 	fprintf(ficlog,"Gaining to use new average direction of P0 P%d instead of biggest increase direction %d :\n",n,ibig);
+  /* The minimization in direction $\xi_1$ gives $P_1$. From $P_1$ minimization in direction $\xi_2$ gives */
+  /* $P_2$. Minimization of line $P_2-P_1$ gives new starting point $P^{(1)}_0$ and direction $\xi_1$ is dropped and replaced by second */
+  /* direction $\xi_1^{(1)}=\xi_2$. Also second direction is replaced by new direction $\xi^{(1)}_2=P_2-P_0$. */
+
+  /* At the second iteration, starting from $P_0^{(1)}$, minimization amongst $\xi^{(1)}_1$ gives point $P^{(1)}_1$. */
+  /* Minimization amongst $\xi^{(1)}_2=(P_2-P_0)$ gives point $P^{(1)}_2$.  As $P^{(2)}_1$ and */
+  /* $P^{(1)}_0$ are minimizing in the same direction $P^{(1)}_2 - P^{(1)}_1= P_2-P_0$, directions $P^{(1)}_2-P^{(1)}_0$ */
+  /* and $P_2-P_0$ (parallel to $\xi$ and $\xi^c$) are conjugate.  } */
+
 	
 #ifdef DEBUG
 	printf("Direction changed  last moved %d in place of ibig=%d, new last is the average:\n",n,ibig);
@@ -4967,7 +4988,7 @@ void mlikeli(FILE *ficres,double p[], in
 
 
   xi=matrix(1,npar,1,npar);
-  for (i=1;i<=npar;i++)
+  for (i=1;i<=npar;i++)  /* Starting with canonical directions j=1,n xi[i=1,n][j] */
     for (j=1;j<=npar;j++)
       xi[i][j]=(i==j ? 1.0 : 0.0);
   printf("Powell\n");  fprintf(ficlog,"Powell\n");