From cbd37725198622e634b1f9b8dbbcef3321cfc839 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Sat, 18 Oct 2025 15:40:02 +0200
Subject: [PATCH] Add variable deltacheck to measure the CKTdelta[0] (most
 recent accepted delta time) versus simulation time. Activated if 'set
 ngdebug' is given (not forget to set '.save deltacheck' if other .save
 commands are given).

---
 src/frontend/outitf.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/frontend/outitf.c b/src/frontend/outitf.c
index d47e61632..6ca75d8d5 100644
--- a/src/frontend/outitf.c
+++ b/src/frontend/outitf.c
@@ -280,6 +280,12 @@ beginPlot(JOB *analysisPtr, CKTcircuit *circuitPtr, char *cktName, char *analNam
                             saves[i].used = 1;
                             break;
                         }
+                        else if (ft_ngdebug && refName && eq(refName, "time") && eq(saves[i].name, "deltacheck")) {
+                            addDataDesc(run, "deltacheck", IF_REAL, j, initmem);
+                            savesused[i] = TRUE;
+                            saves[i].used = 1;
+                            break;
+                        }
                     }
                 }
             }
@@ -307,6 +313,7 @@ beginPlot(JOB *analysisPtr, CKTcircuit *circuitPtr, char *cktName, char *analNam
             /* generate a vector of real time information */
             if (ft_ngdebug && refName && eq(refName, "time")) {
                  addDataDesc(run, "speedcheck", IF_REAL, numNames, initmem);
+                 addDataDesc(run, "deltacheck", IF_REAL, numNames, initmem);
             }
         }
 
@@ -582,6 +589,9 @@ OUTpD_memory(runDesc *run, IFvalue *refValue, IFvalue *valuePtr)
                 double tt = ((double)cl - (double)startclock) / CLOCKS_PER_SEC;
                 plotAddRealValue(d, tt);
             }
+            else if (ft_ngdebug && d->type == IF_REAL && eq(d->name, "deltacheck")) {
+                plotAddRealValue(d, ft_curckt->ci_ckt->CKTdeltaOld[0]);
+            }
             else if (d->type == IF_REAL)
                 plotAddRealValue(d, valuePtr->v.vec.rVec[d->outIndex]);
             else if (d->type == IF_COMPLEX)
@@ -693,6 +703,9 @@ OUTpData(runDesc *plotPtr, IFvalue *refValue, IFvalue *valuePtr)
                     double tt = ((double)cl - (double)startclock) / CLOCKS_PER_SEC;
                     fileAddRealValue(run->fp, run->binary, tt);
                 }
+                else if (ft_ngdebug && run->data[i].type == IF_REAL && eq(run->data[i].name, "deltacheck")) {
+                    fileAddRealValue(run->fp, run->binary, ft_curckt->ci_ckt->CKTdeltaOld[0]);
+                }
                 else if (run->data[i].type == IF_REAL)
                     fileAddRealValue(run->fp, run->binary,
                             valuePtr->v.vec.rVec [run->data[i].outIndex]);
@@ -970,6 +983,8 @@ guess_type(const char *name, char* pltypename)
         type = SV_TIME;
     else if ( cieq(name, "speedcheck"))
         type = SV_TIME;
+    else if ( cieq(name, "deltacheck"))
+        type = SV_TIME;
     else if (cieq(name, "frequency"))
         type = SV_FREQUENCY;
     else if (ciprefix("inoise", name))