From 7009f839e896d80ed93e34277688bf79b6c71192 Mon Sep 17 00:00:00 2001
From: nadolski <nadolski@9a6e40ed-f3a0-4838-9b4a-bf418f78e88d>
Date: Fri, 1 Oct 2010 16:44:49 +0000
Subject: [PATCH] Ring_GetChroma modify. As in Tracy II, convergence test
introduced since at commonDP (10-10) the computing precision is low.
---
tracy/tracy/src/t2ring.cc | 137 +++++++++++++++++++++++++-------------
1 file changed, 92 insertions(+), 45 deletions(-)
diff --git a/tracy/tracy/src/t2ring.cc b/tracy/tracy/src/t2ring.cc
index 00b0a46..b88a96d 100644
--- a/tracy/tracy/src/t2ring.cc
+++ b/tracy/tracy/src/t2ring.cc
@@ -475,56 +475,103 @@ void Cell_Twiss(long i0, long i1, ss_vect<tps> &Ascr, bool chroma, bool ring,
WARNING : this routine does not give the chromaticities for dP != 0
but the local slope of the curve xi=f(dP)
16/10/03 Modified convergence test: now done for both planes
+ 01/09/10 Modify the convergence criteria on relative diff of the chroma value
+ The previous test does not work well for non zero chromaticities
****************************************************************************/
#define n 4
-void Ring_Getchrom(double dP)
-{
- long int lastpos = 0;
- int j;
- Vector2 alpha = {0.0, 0.0}, beta = {0.0, 0.0}, gamma = {0.0, 0.0};
- Vector2 nu = {0.0, 0.0}, nu0 = {0.0, 0.0};
-
- if (dP != 0.0)
- fprintf(stdout,"Ring_Getchrom: Warning this is NOT the CHROMA, dP=%e\n",
- dP);
-
- /* Get cod for energy dP - globval.dPcommon*/
- GetCOD(globval.CODimax, globval.CODeps, dP-globval.dPcommon*0.5, lastpos);
-
- if (!status.codflag) {
- /* if no cod */
- fprintf(stdout,"Ring_Getchrom: Lattice is unstable for"
- " dP-globval.dPcommon=% .5e\n", dP-globval.dPcommon*0.5);
- return;
- }
-
- /* get tunes for energy dP - globval.dPcommon/2 from oneturn matrix */
- Cell_GetABGN(globval.OneTurnMat, alpha, beta, gamma, nu0);
-
- /* Get cod for energy dP+globval.dPcommon*/
- GetCOD(globval.CODimax, globval.CODeps, dP+globval.dPcommon*0.5, lastpos);
-
- if (!status.codflag) { /* if no cod */
- fprintf(stdout,"Ring_Getchrom Lattice is unstable for"
- " dP+globval.dPcommon=% .5e \n", dP+globval.dPcommon*0.5);
- return;
- }
-
- /* get tunes for energy dP+globval.dPcommon/2 from one turn matrix */
- Cell_GetABGN(globval.OneTurnMat, alpha, beta, gamma, nu);
-
- if (!globval.stable) {
- printf("Ring_Getchrom: Lattice is unstable\n");
- }
-
- /* Get chromaticities by numerical differentiation*/
- for (j = 0; j <= 1; j++)
- globval.Chrom[j] = (nu[j]-nu0[j])/globval.dPcommon;
-
- status.chromflag = true;
+#define chromeps 1e-6 /* convergence condition for chromaticity computation */
+#define LOG10 log(10.0)
+
+void Ring_Getchrom(double dP) {
+ long int lastpos = 0;
+ double NORMchro = 1.0;
+ double dPlocal = 0.0, expo = 0.0, Norm_TEMP = 0.0;
+ int j;
+ Vector2 alpha = { 0.0, 0.0 }, beta = { 0.0, 0.0 }, gamma = { 0.0, 0.0 };
+ Vector2 nu = { 0.0, 0.0 }, nu0 = { 0.0, 0.0 }, TEMP={0.0,0.0}, Chrom={0.0,0.0};;
+
+ if (dP != 0.0)
+ fprintf(stdout,
+ "Ring_Getchrom: Warning this is NOT the CHROMA, dP=%e\n", dP);
+
+ /* initialization */
+ globval.Chrom[0] = 1e38;
+ globval.Chrom[1] = 1e38;
+
+ expo = log(globval.dPcommon) / LOG10;
+ do {
+ for (j = 0; j <= 1; j++)
+ Chrom[j] = globval.Chrom[j];
+
+ dPlocal = exp(expo * LOG10);
+ //Get cod for energy dP - globval.dPcommon
+ GetCOD(globval.CODimax, globval.CODeps, dP - dPlocal * 0.5, lastpos);
+
+ if (!status.codflag) {
+ // if no cod
+ fprintf(stdout, "Ring_Getchrom: Lattice is unstable for"
+ " dP-globval.dPcommon=% .5e\n", dP - dPlocal * 0.5);
+ return;
+ }
+
+ //get tunes for energy dP - globval.dPcommon/2 from oneturn matrix
+ Cell_GetABGN(globval.OneTurnMat, alpha, beta, gamma, nu0);
+
+ //Get cod for energy dP+globval.dPcommon
+ GetCOD(globval.CODimax, globval.CODeps, dP + dPlocal * 0.5, lastpos);
+
+ if (!status.codflag) { // if no cod
+ fprintf(stdout, "Ring_Getchrom Lattice is unstable for"
+ " dP+globval.dPcommon=% .5e \n", dP + dPlocal * 0.5);
+ return;
+ }
+
+ //get tunes for energy dP+globval.dPcommon/2 from one turn matrix
+ Cell_GetABGN(globval.OneTurnMat, alpha, beta, gamma, nu);
+
+ if (!globval.stable) {
+ printf("Ring_Getchrom: Lattice is unstable\n");
+ }
+
+ //Get chromaticities by numerical differentiation
+ for (j = 0; j <= 1; j++)
+ globval.Chrom[j] = (nu[j] - nu0[j]) / globval.dPcommon;
+
+ /* Get chromaticities by numerical differentiation*/
+ for (j = 0; j <= 1; j++) {
+ globval.Chrom[j] = (nu[j] - nu0[j]) / dPlocal;
+ TEMP[j] = fabs(globval.Chrom[j] - Chrom[j]);
+ }
+
+ Norm_TEMP = sqrt(TEMP[0] * TEMP[0] + TEMP[1] * TEMP[1]);
+ NORMchro = sqrt(globval.Chrom[0] * globval.Chrom[0] + globval.Chrom[1]
+ * globval.Chrom[1]);
+
+ // TEST CHROMA convergence
+ if (trace) {
+ fprintf(
+ stdout,
+ "\nexpo % e xix = % e xiz = % e Norm_TEMP = %e TEMPX %+e TEMPZ %+e\n",
+ expo, Chrom[0], Chrom[1], Norm_TEMP, TEMP[0], TEMP[1]);
+ fprintf(stdout, "expo % e nux = % e nuz = % e dPlocal= %+e\n",
+ expo, nu0[0], nu0[1], dP - 0.5 * dPlocal);
+ fprintf(stdout, "expo % e nux = % e nuz = % e dPlocal= %+e\n",
+ expo, nu[0], nu[1], dP + 0.5 * dPlocal);
+ }
+ expo += 1.0;
+ if (trace)
+ fprintf(stdout, "%+e %+.12e %+.12e %+.12e %+.12e\n", dPlocal,
+ globval.Chrom[0], fabs(globval.Chrom[0] - Chrom[0])
+ / Chrom[0], globval.Chrom[1], fabs(globval.Chrom[1]
+ - Chrom[1]) / Chrom[1]);
+ } while ((Norm_TEMP > chromeps * NORMchro) || (Norm_TEMP == 0e0));
+
+ status.chromflag = true;
}
#undef n
+#undef chromeps
+#undef LOG10
/****************************************************************************/
--
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