diff --git a/pub/lib/opr.cpp b/pub/lib/opr.cpp
index fabae83fd1dc0b20fac1f8f96b753579715bf4ff..97cc46ce2ef325bbbb6d5cd60f83d2740ee04e38 100644
--- a/pub/lib/opr.cpp
+++ b/pub/lib/opr.cpp
@@ -283,9 +283,9 @@ void NOperate::Integral()
             else
                 fout = POld((dynamic_cast<const COld*>(fin))->new_POld());
             fout->log_action("oi " + expr);
-            fout->ZCo.pop_back();
             fout->xco = fin->ZCo.back();
             fout->yco = T->node_coord(k);
+            fout->ZCo.pop_back();
             sout = PSpec(new CSpec);
             sout->z = fin->V[0]->z;
             sout->z.pop_back();
@@ -300,14 +300,14 @@ void NOperate::Integral()
                 cout << "result: " << res->to_s() << "\n";
                 continue;
             }
-            xval = fin->V[j]->z[nz - 1]->to_r();
+            xval = fin->V[j]->z[nz-1]->to_r();
             sout->push_xyd(xval, res->to_r(), res->to_dr());
-            if (nz >= 2) { // new spectrum if jump in other z values
-                double zval = fin->V[j]->z[nz - 2]->to_r();
-                if (j + 1 < fin->nJ() && fin->V[j + 1]->z[nz - 2]->to_r() != zval) {
+            if (nz > 1) { // new spectrum if jump in other z values
+                if (j+1 < fin->nJ()
+		   && fin->V[j+1]->z[nz-2]->to_r() != fin->V[j]->z[nz-2]->to_r()) {
                     fout->V.push_back(move(sout));
                     sout = PSpec(new CSpec);
-                    sout->z = fin->V[j + 1]->z;
+                    sout->z = fin->V[j+1]->z;
                     sout->z.pop_back();
                 }
             }
@@ -350,22 +350,22 @@ void NOperate::IntXY(string mode)
         if (icold < 0)
             return;
     }
-    xco = CCoord("x", "");
-    yco = CCoord("y", "");
 
     while (const COld* fin = fiter.nextD()) {
-        int nz = fin->ZCo.size();
-
         POld fout(fin->new_POld());
         string lin = S("oi") + mode + " " + S(icolx) + " " + S(icoly);
         if (with_d)
             lin += " " + S(icold);
         fout->log_action(lin);
 
-        fout->xco = xco;
-        fout->yco = yco;
+        fout->xco = CCoord("x", "");
+        fout->yco = CCoord("y", "");
+        fout->ZCo.pop_back();
+        int nz = fin->ZCo.size();
 
         PSpec sout(new CSpec);
+        sout->z = fin->V[0]->z;
+        sout->z.pop_back();
 
         for (int j = 0; j < fin->nJ(); j++) {
             int n = fin->nPts(j);
@@ -376,11 +376,13 @@ void NOperate::IntXY(string mode)
             else
                 sout->push_xy(fin->VS(j)->y[icolx], fin->VS(j)->y[icoly]);
             sout->z = fin->VS(j)->z;
-            if (nz > 2) { // new spectrum if jump in other z value
-                if (j + 1 < fin->nJ()
-                    && fin->V[j + 1]->z[nz - 2]->to_r() != fin->V[j]->z[nz - 2]->to_r()) {
+            if (nz > 1) { // new spectrum if jump in other z value
+                if (j+1 < fin->nJ()
+                    && fin->V[j+1]->z[nz-2]->to_r() != fin->V[j]->z[nz-2]->to_r()) {
                     fout->V.push_back(move(sout));
                     sout = PSpec(new CSpec);
+                    sout->z = fin->V[j+1]->z;
+                    sout->z.pop_back();
                 }
             }
         }
@@ -389,7 +391,6 @@ void NOperate::IntXY(string mode)
     }
 }
 
-
 //**************************************************************************************************
 //*  functional operations
 //**************************************************************************************************