phase.gp: Add gnuplot script and rules to build a phase-space plot

In phase.gp, I use a for loop to iterate over data block (in this
case, each trajectory is in its own block).  This gives you nice
per-block colors, but means you'll have to update the loop if you
change the number of energies you're looping over.

diff --git a/Makefile b/Makefile
index 44e3fe2a6c251de40294168eb9b6a5d0de71b9c3..89dac64592a60f394a90c44da44f65d5580f07d2 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -138,7 +138,7 @@ $(CXX_PROGRAMS): % : $$($$(*)_OBJECTS)
 #     gnuplot plot.gp
 # where plot.gp was a gnuplot script for plotting data generated by
 # RUN_PROGRAM.
-run: error.png
+run: error.png phase.png
 
 .SECONDEXPANSION:
 error-%.data: $(PROGRAMS)
@@ -152,6 +152,17 @@ error-%.data: $(PROGRAMS)
 error.png: error.gp error-euler.data error-midpoint.data error-rk4.data
        gnuplot "$<" > "$@"
 
+phase.data:
+       > "$@"
+       for E in 0.1 0.5 1 1.5 2 2.5 3 3.5 4 4.5 4.9 5 5.1 5.5; do \
+               ./one_gaussian_bump --vx0-energy "$$E" >> "$@"; \
+               echo >> "$@"; \
+               echo >> "$@"; \
+       done
+
+phase.png: phase.gp phase.data
+       gnuplot "$<" > "$@"
+
 # Pattern rule for compiling object files from C++ source
 # There is an implicit rule for this in GNU make
 #   http://www.gnu.org/software/make/manual/html_node/Catalogue-of-Rules.html

diff --git a/phase.gp b/phase.gp
new file mode 100644 (file)
index 0000000..7cc02aa
--- /dev/null
+++ b/phase.gp
@@ -0,0 +1,12 @@
+set term png
+set termoption enhanced
+set title 'Phase space'
+set xlabel 'x'
+set ylabel 'v_x'
+unset key
+set yrange [-4.5:0.5]
+k = -5
+b = 1
+V(r) = 0.5 * k * b**2 * exp(-r**2/b**2)
+set style data lines
+plot V(x) title 'V(r)', for [i=0:13] 'phase.data' index i using 2:4