CFLAGS = -pthread -Ofast
LDLIBS = -pthread

#q := $(shell seq 10 1 19)
#N := $(shell for i in $q; do \echo "e($$i)"|bc -l; done)
powers := $(shell seq 13 1 25)
N := $(shell for i in $(powers); do echo "2^($$i)"|bc -l; done)

conv.svg:out.txt Makefile
	gnuplot -e "\
	set title 'Convergence of pi(n) as function of n';\
	set term svg background rgb 'white';\
	set out '$@';\
	set log y;\
	set log x;\
	set xlabel 'n';\
	pi=3.1415927;\
	a=1;\
	f(x)=a/sqrt(x);\
	fit f(x) '$<' u 1:(abs((\$$2)-pi)):(1/sqrt(\$$1)) via a;\
	plot\
	 '$<' u 1:(abs((\$$2)-pi)) with linespoints title 'abs(pi(n)-pi)'\
	,f(x) with lines title sprintf('%.2g/sqrt(n)',a);\
	"

out.txt:main
	cat /dev/null > $@
	for n in $N; do echo $$n; ./$< -n $$n >> $@; done

clean:
	$(RM) main out.txt conv.svg

test:
	echo $(powers)
	echo $N
	echo $(word 1,$N)