1 files changed, 33 insertions, 0 deletions
diff --git a/class/putParticleInBox.f90 b/class/putParticleInBox.f90
new file mode 100644
index 0000000..d98a116
--- /dev/null
+++ b/class/putParticleInBox.f90
@@ -0,0 +1,33 @@
+   ! intakes coordinates and outputs index
+   integer function indexfxn(px, py) result(idx)
+     double precision, intent(in) :: px, py
+     double precision :: boxSize,yCoord
+      integer :: ix, iy
+
+     !> Check if particle is in box
+     if(abs(px).GT.L/2 .OR. abs(py).GT.L/2) then
+         !> Particle is outside, don't track it
+         idx=b*b ! This is the "recycle bin" for untracked particles.
+     else
+      ! the sector size      
+      ! M = floor(L / rc)
+      yCoord = - py
+      ! coordinate + half length of boundary [-L/2,L/2] -> [0,L] 
+      ! divided by effective particle size to give coordinate
+      boxSize=L/real(b,8)
+      ix = floor((px + L/2.0d0)/boxSize)
+      iy = floor((yCoord + L/2.0d0)/boxSize)
+
+      ! for particles on the boundary
+      ix = min(max(ix, 0), b-1)
+      iy = min(max(iy, 0), b-1)
+      if (ix < 0 .or. ix >= b .or. iy < 0 .or. iy >= b) then
+         print *, "ERROR: particle outside sector grid"
+         print *, "px, py =", px, py
+         stop
+      end if
+
+      ! call rey's function
+      idx = TWOtoONE(ix,iy)
+     end if
+   end function indexfxn