Solving Equation by Iteration

[Andrew_F_1]

Hello,

I wrote the following code to solve an equation by iteration but I never get a reasonable answer.

do f=0.0000,180.0000
y= (Thita_ow*pi/180d0) + (f*pi/180d0) - pi - ((cos(Thita_ow*pi/180d0)*cos((Thita_ow-Half_Angle)*pi/180d0))/(sin(Half_Angle*pi/180))) &
   + ((2*cos(Thita_ow*pi/180d0)-cos(f*pi/180d0))*((cos((f+Half_Angle)*pi/180d0))/(sin(Half_Angle*pi/180d0))))
if (y==0.0) exit
end do

! Creating the TxT file
open(unit=3 , file='test.txt')
write(3,*) f, y
close(unit=3)

Any help ?

[jimdempseyatthecove]

David brings up a good point.

If the function produces what is called a telephone pole graph (a series of punctuated points), then most search algorithms will get stuck on the first pole encountered. This "pole" may not necessarily be the tallest. Before you get hung up on the telephone pole analogy, consider a wave form of multiple frequencies. This wave form has multiple localized crests (and troughs), any of which might constrict the search.

Jim Dempsey