Compile both CPU and GPU versions together

Signed-off-by: Rafael Ravedutti <rafaelravedutti@gmail.com>

Makefile

-.PHONY: all build clean lj_ns
+.PHONY: all build clean lj_ns_cpu lj_ns_gpu
 
-all: build lj_ns
+all: build lj_ns_cpu lj_ns_gpu
 	@echo "Everything was done!"
 
 build:
 	@echo "Building pairs package..."
 	python3 setup.py build && python3 setup.py install --user
 
-lj_ns:
-	@echo "Generating and compiling CPP for Lennard-Jones example..."
-	python3 examples/lj_func.py
+lj_ns_cpu:
+	@echo "Generating and compiling Lennard-Jones example for CPU..."
+	python3 examples/lj_func.py cpu
+
+lj_ns_gpu:
+	@echo "Generating and compiling Lennard-Jones example for GPU..."
+	python3 examples/lj_func.py gpu
 
 # Targets
-cpu: build lj_ns
+cpu: build lj_ns_cpu
 	g++ -o lj_ns lj_ns.cpp
 
-gpu: build lj_ns
+gpu: build lj_ns_gpu
 	nvcc -o lj_ns lj_ns.cu
 
 clean:
 	@echo "Cleaning..."
-	rm -rf build lj_ns lj_ns.cpp dist pairs.egg-info functions functions.pdf
+	rm -rf build lj_ns lj_ns.cpp lj_ns.cu dist pairs.egg-info functions functions.pdf

examples/lj_func.py

 import pairs
+import sys
 
 
 def lj(i, j):
@@ -12,6 +13,12 @@ def euler(i):
     position[i] += dt * velocity[i]
 
 
+cmd = sys.argv[0]
+target = sys.argv[1] if len(sys.argv[1]) > 1 else "none"
+if target != 'cpu' and target != 'gpu':
+    print(f"Invalid target, use {cmd} <cpu/gpu>")
+
+
 dt = 0.005
 cutoff_radius = 2.5
 skin = 0.3
@@ -32,5 +39,10 @@ psim.vtk_output("output/test")
 psim.compute(lj, cutoff_radius, {'sigma6': sigma6, 'epsilon': epsilon})
 psim.compute(euler, symbols={'dt': dt})
 psim.target(pairs.target_cpu())
-#psim.target(pairs.target_gpu())
+
+if target == 'gpu':
+    psim.target(pairs.target_gpu())
+else:
+    psim.target(pairs.target_cpu())
+
 psim.generate()