diff --git a/LPFP.cabal b/LPFP.cabal
--- a/LPFP.cabal
+++ b/LPFP.cabal
@@ -1,12 +1,12 @@
 name:           LPFP
-version:        1.1.5
+version:        1.2.1
 synopsis:       Code for the book Learn Physics with Functional Programming
 description:    Haskell code to help the user learn mechanics of one particle,
                 mechanics of multiple interacting particles, and electromagnetic theory.
 homepage:       https://lpfp.io
 author:         Scott N. Walck
 maintainer:     walck@lvc.edu
-copyright:      2024 Scott N. Walck
+copyright:      2024-2025 Scott N. Walck
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
@@ -37,8 +37,8 @@
       base >= 4.7 && < 5,
       containers >= 0.6.7 && < 0.8,
       Vis >= 1.0.0 && < 1.1,
-      diagrams-cairo >= 1.4.2 && < 1.5,
-      diagrams-lib >= 1.4.6 && < 1.5,
+      diagrams-cairo >= 1.4.2 && < 1.6,
+      diagrams-lib >= 1.4.6 && < 1.6,
       gloss >= 1.13.2 && < 1.14,
       gnuplot >= 0.5.7 && < 0.6,
       linear >= 1.22 && < 1.24
diff --git a/src/LPFP/ElectricField.hs b/src/LPFP/ElectricField.hs
--- a/src/LPFP/ElectricField.hs
+++ b/src/LPFP/ElectricField.hs
@@ -195,8 +195,14 @@
       in zip ps (drop 1 ps)
 
 linSpaced :: Int -> R -> R -> [R]
-linSpaced n x0 x1 = take (n+1) [x0, x0+dx .. x1]
-    where dx = (x1 - x0) / fromIntegral n
+linSpaced n x0 x1
+    = let dx  = (x1 - x0) / fromIntegral n
+          try = take n [x0, x0+dx .. x1] ++ [x1]
+      in if length try == n + 1
+         then try
+         else if length try == 1
+              then replicate (n + 1) x0
+              else error "linSpaced is facing difficulties"
 
 surfaceSample :: Int -> Surface -> [(Position,Vec)]
 surfaceSample n s = [(triCenter tri, triArea tri) | tri <- triangles n s]