/* example problem for fma_ra.rpn 
/* solves x'' + kx = 0 for value at t=tlim
0 sto k sto tlim sto dt sto x sto x' sto t sto dt 

udf
setup
.1 sto k
1 sto x
0 sto x'
0 sto t
.08 sto dt 
500 * sto tlim


"fma_ra.rpn,s" @
udf
fn
k chs *

udf
end
pop tlim - chs abs dt 100 / < 

udf
go
solve
t 1 "t = %le\n" fprf
x 1 "x = %le\n" fprf
x' 1 "x' = %le\n" fprf
x' sqr k / x sqr + 1 "amplitude = %le\n" fprf
3 popn
cle