From 9013106e09e2b380e93df8f1a79153630885d185 Mon Sep 17 00:00:00 2001
From: Connor Moore <connor@hhmoore.ca>
Date: Wed, 25 Feb 2026 12:47:03 -0500
Subject: Forced real64 for everything and added gitignore

---
 .gitignore                   | 10 ++++++++
 new/self-langevin-motion.f90 | 54 ++++++++++++++++++++++----------------------
 2 files changed, 37 insertions(+), 27 deletions(-)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6022cc9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,10 @@
+new/prog
+class/prog
+
+new/*_results
+new/*.out
+new/*.mod
+
+class/*_results
+class/*.out
+class/*.mod
diff --git a/new/self-langevin-motion.f90 b/new/self-langevin-motion.f90
index 167da70..6c048d9 100644
--- a/new/self-langevin-motion.f90
+++ b/new/self-langevin-motion.f90
@@ -7,19 +7,19 @@ program langevin_motion
 
     !> Define some basic parameters
     integer(int64), parameter :: n = 1000
-    real(real64), parameter :: pi = 2.0*asin(1.0)
-    real(real64), parameter :: L = 1.0
+    real(real64), parameter :: pi = 2.0_real64*asin(1.0_real64)
+    real(real64), parameter :: L = 1.0_real64
 
     !> Numerical constants and such
-    real(real64), parameter :: dt = 0.005
-    real(real64), parameter :: t_max = 10.0
-    real(real64), parameter :: kT = 10.0
-    real(real64), parameter :: g = 1.0
-    real(real64), parameter :: m = 1.0
-    real(real64), parameter :: eps = 1.0
-    real(real64), parameter :: sigma = 1E-03
-    real(real64), parameter :: rc = sigma*2**(1.0/6.0)
-    real(real64), parameter :: pref1 = g, pref2 = sqrt(24.0*kT*g/dt)
+    real(real64), parameter :: dt = 0.005_real64
+    real(real64), parameter :: t_max = 10.0_real64
+    real(real64), parameter :: kT = 10.0_real64
+    real(real64), parameter :: g = 1.0_real64
+    real(real64), parameter :: m = 1.0_real64
+    real(real64), parameter :: eps = 1.0_real64
+    real(real64), parameter :: sigma = 1E-03_real64
+    real(real64), parameter :: rc = sigma*2**(1.0_real64/6.0_real64)
+    real(real64), parameter :: pref1 = g, pref2 = sqrt(24.0_real64*kT*g/dt)
 
     !> And non-constants
     real(real64) :: t
@@ -39,8 +39,8 @@ program langevin_motion
     do while (t .lt. t_max)
 
         !> Update half-step velocities
-        vhx = vx + 0.5*ax*dt
-        vhy = vy + 0.5*ay*dt
+        vhx = vx + 0.5_real64*ax*dt
+        vhy = vy + 0.5_real64*ay*dt
 
         !> Update the positions
         px = px + vhx*dt
@@ -50,13 +50,13 @@ program langevin_motion
         call impose_BC(px, py, vhx, vhy, is_tracked, L)
 
         !> Find the new acceleration
-        ax = 0.0
-        ay = 0.0
+        ax = 0.0_real64
+        ay = 0.0_real64
 
         call random_number(ran1)
-        ran1 = ran1 - 0.5
+        ran1 = ran1 - 0.5_real64
         call random_number(ran2)
-        ran2 = ran2 - 0.5
+        ran2 = ran2 - 0.5_real64
 
         !> Random force
         ax = ax - pref1*vhx + ran1
@@ -74,12 +74,12 @@ program langevin_motion
             are_interacting = (dn .gt. 0.0) .and. (dn .lt. rc) .and. is_tracked
 
             !> Start with no forces
-            F = 0.0
+            F = 0.0_real64
 
             where (are_interacting)
 
                 !> Lennardn-Jones force
-                F = 4.0*eps*(-12.0*sigma**12/dn**13 + 6.0*sigma**6/dn**7)
+                F = 4.0_real64*eps*(-12.0_real64*sigma**12/dn**13 + 6.0_real64*sigma**6/dn**7)
 
             end where
 
@@ -90,8 +90,8 @@ program langevin_motion
         end do interactions
 
         !> Update full velocities
-        vx = vhx + 0.5*ax*dt
-        vy = vhy + 0.5*ay*dt
+        vx = vhx + 0.5_real64*ax*dt
+        vy = vhy + 0.5_real64*ay*dt
 
         !> Update timestep
         t = t + dt
@@ -120,20 +120,20 @@ contains
         call random_number(ran2)
 
         !> Initial position
-        px = L*(ran1-0.5)
-        py = L*(ran2-0.5)
+        px = L*(ran1-0.5_real64)
+        py = L*(ran2-0.5_real64)
 
         !> Initial acceleration is zero
-        ax = 0.0
-        ay = 0.0
+        ax = 0.0_real64
+        ay = 0.0_real64
 
         !> New random numbers
         call random_number(ran1)
         call random_number(ran2)
 
         !> Initial velocity using Box-Muller transform
-        vx = sqrt(kT/m)*sqrt(-2.0*log(ran1))*cos(2*pi*ran2)
-        vy = sqrt(kT/m)*sqrt(-2.0*log(ran1))*sin(2*pi*ran2)
+        vx = sqrt(kT/m)*sqrt(-2.0_real64*log(ran1))*cos(2.0_real64*pi*ran2)
+        vy = sqrt(kT/m)*sqrt(-2.0_real64*log(ran1))*sin(2.0_real64*pi*ran2)
 
     end subroutine initialize_particles
 
-- 
cgit v1.2.3