From 422a20540990db0cdbb7d8587023f3140efb7423 Mon Sep 17 00:00:00 2001
From: Giles Atkinson <“gatk555@gmail.com”>
Date: Tue, 2 May 2023 12:08:21 +0100
Subject: [PATCH] Always propgate any individual scale for a vector that
 appears in an expression, resolving conflicts by matching length and warning
 only when making an arbitary choice.  One effect of this is that it is now
 possible to mix analog nodes with offset digital nodes (an expression like
 dvalue+6) without a warning and get a correct plot.

---
 src/frontend/evaluate.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/frontend/evaluate.c b/src/frontend/evaluate.c
index f38aff246..ee9bec045 100644
--- a/src/frontend/evaluate.c
+++ b/src/frontend/evaluate.c
@@ -191,7 +191,7 @@ doop(char what,
     struct dvec *v1, *v2, *res;
     ngcomplex_t *c1 = NULL, *c2 = NULL, lc;
     double *d1 = NULL, *d2 = NULL, ld;
-    int length = 0, i;
+    int length = 0, i, longer;
     void *data;
     bool free1 = FALSE, free2 = FALSE, relflag = FALSE;
 
@@ -253,6 +253,7 @@ doop(char what,
     /* Make sure we have data of the same length. */
     length = ((v1->v_length > v2->v_length) ? v1->v_length : v2->v_length);
     if (v1->v_length < length) {
+        longer = 2;
         free1 = TRUE;
         if (isreal(v1)) {
             ld = 0.0;
@@ -275,6 +276,7 @@ doop(char what,
                 c1[i] = lc;
         }
     } else {
+        longer = 0;
         if (isreal(v1))
             d1 = v1->v_realdata;
         else
@@ -282,6 +284,7 @@ doop(char what,
     }
 
     if (v2->v_length < length) {
+        longer = 1;
         free2 = TRUE;
         if (isreal(v2)) {
             ld = 0.0;
@@ -335,10 +338,27 @@ doop(char what,
     }
 
     /* This is a non-obvious thing */
+
     if (v1->v_scale != v2->v_scale) {
-        fprintf(cp_err, "Warning: scales of %s and %s are different.\n",
-                v1->v_name, v2->v_name);
-        res->v_scale = NULL;
+        switch (longer) {
+        case 0:
+            if (!v1->v_scale)
+                res->v_scale = v2->v_scale;
+            else if (!v2->v_scale)
+                res->v_scale = v1->v_scale;
+            else
+                fprintf(cp_err,
+                         "Warning: scales of %s and %s are different.\n",
+                        v1->v_name, v2->v_name);
+            res->v_scale = v1->v_scale; // Do something!
+            break;
+        case 1:
+            res->v_scale = v1->v_scale;
+            break;
+        case 2:
+            res->v_scale = v2->v_scale;
+            break;
+        }
     } else {
         res->v_scale = v1->v_scale;
     }