diff --git a/bar1d-python/PrePost.py b/bar1d-python/PrePost.py
index 6cef401..851c1ab 100755
--- a/bar1d-python/PrePost.py
+++ b/bar1d-python/PrePost.py
@@ -97,7 +97,7 @@ def setup_ID_LM():
         if model.flags[i] == 2:   # Essential boundary node
             count = count + 1      
             model.ID[i] = count   # The reordered number of essential B.C
-            model.d[count] = model.e_bc[i] 
+            model.d[count-1] = model.e_bc[i] 
         else:
             count1 = count1 + 1
             model.ID[i] = model.nd + count1
@@ -112,7 +112,7 @@ def naturalBC():
     for i in range(model.neq):
        if model.flags[i] == 1:
           node = model.ID[i]-1
-          model.f[node] += model.CArea[node]*model.n_bc[node]
+          model.f[node] += model.CArea[i]*model.n_bc[i]
 
     
 def plotbar():
@@ -251,4 +251,4 @@ def postprocessor():
     # Convert matplotlib figures into PGFPlots figures stored in a Tikz file, 
     # which can be added into your LaTex source code by "\input{fe_plot.tex}"
     if model.plot_tex == "yes":
-        tikzplotlib.save("fe_plot.tex")
\ No newline at end of file
+        tikzplotlib.save("fe_plot.tex")
diff --git a/beam1d-python/PrePost.py b/beam1d-python/PrePost.py
index 296d1cf..7302696 100644
--- a/beam1d-python/PrePost.py
+++ b/beam1d-python/PrePost.py
@@ -95,7 +95,7 @@ def setup_ID_LM():
 		if model.flags[i] == 2:		# Essential boundary node
 			count += 1
 			model.ID[i] = count		# The reordered number of essential B.C
-			model.d[count] = model.e_bc[i]
+			model.d[count-1] = model.e_bc[i]
 		else:
 			count1 += 1
 			model.ID[i] = model.nd + count1
@@ -112,7 +112,7 @@ def naturalBC():
 	for i in range(model.neq):
 		if model.flags[i] == 1:
 			dof = model.ID[i] - 1
-			model.f[dof] += model.n_bc[dof]
+			model.f[dof] += model.n_bc[i]
 
 
 def plotbeam():
@@ -249,4 +249,4 @@ def postprocessor():
 	# Convert matplotlib figures into PGFPlots figures stored in a Tikz file,
 	# which can be added into your LaTex source code by "\input{fe_plot.tex}"
 	if model.plot_tex == "yes":
-		tikzplotlib.save("fe_plot.tex")
\ No newline at end of file
+		tikzplotlib.save("fe_plot.tex")