From 4ac7a26fe13e68a640a455a0d828f4e662ff23ee Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Mon, 18 May 2020 19:35:50 -0400
Subject: [PATCH] add support for extracting r0 array to bond style zero

---
 src/bond_zero.cpp | 11 +++++++++--
 src/bond_zero.h   |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/bond_zero.cpp b/src/bond_zero.cpp
index 428fd0ace2..cb336ddd67 100644
--- a/src/bond_zero.cpp
+++ b/src/bond_zero.cpp
@@ -144,8 +144,6 @@ void BondZero::write_data(FILE *fp)
     fprintf(fp,"%d %g\n",i,r0[i]);
 }
 
-
-
 /* ---------------------------------------------------------------------- */
 
 double BondZero::single(int /*type*/, double /*rsq*/, int /*i*/, int /*j*/,
@@ -153,3 +151,12 @@ double BondZero::single(int /*type*/, double /*rsq*/, int /*i*/, int /*j*/,
 {
   return 0.0;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void *BondZero::extract(const char *str, int &dim)
+{
+  dim = 1;
+  if (strcmp(str,"r0")==0) return (void*) r0;
+  return NULL;
+}
diff --git a/src/bond_zero.h b/src/bond_zero.h
index 7cbd2b9a96..b31e89edf7 100644
--- a/src/bond_zero.h
+++ b/src/bond_zero.h
@@ -38,6 +38,7 @@ class BondZero : public Bond {
   void write_data(FILE *);
 
   double single(int, double, int, int, double &);
+  virtual void *extract(const char *, int &);
 
  protected:
   double *r0;