How to stop getting zeros returned in python?

Question

Hi there trying to just get values for simple fractions like 1/225 or 35/75 but it keeps returning zeros? Any help would be appreciated!

mymatrix=[[0,1,1],[1,0,1],[1,1,0]]
uu=len(mymatrix)
initials_ss=[[150],[300],[100]]    #Your initial population size suceptibles
initials_zz=[[5],[15],[555]]    #Your initial population size zombies
initials_rr=[[0],[0],[0]]   #Your initial population size removed
s_n=np.matrix(initials_ss)   #Initial value suceptibles vector
z_n=np.matrix(initials_zz)   #Initial value zombie vector
r_n=np.matrix(initials_rr)   #Initial value removed vector

z_nn=np.array(initials_zz)
ss=np.sum(s_n,axis=0)
zz=np.sum(z_n,axis=0)
rr=np.sum(r_n,axis=0)

N=ss+zz+rr
NN=1/N[0]
tt=np.zeros((uu,uu),int)
np.fill_diagonal(tt,NN)
print(tt)
print(NN)
u=np.diag(z_n[:,0])
t=NN*(u*s_n)
print(t)

so when you try to find NN you get a matrix filled by zeros on the diagonals but it should have the values of the fractions?

Could you post your code so we can see how you tried to implement it? — Tehc, Nov 08 '16 at 10:26

hrishi · Answer 1 · 2016-11-08T10:32:49.160

-1

Use type casting. As in python you have to type cast explicitly. The following will do your job.

In [92]: float(1)/float(225)
Out[92]: 0.0044444444444444444 

In [95]: float(1)/225
Out[95]: 0.0044444444444444444

In [96]: 1/float(225)
Out[96]: 0.0044444444444444444

edited Nov 08 '16 at 10:32

answered Nov 08 '16 at 10:28

hrishi

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1

Casting either the numerator or the denominator is sufficient. – Anthony Labarre Nov 08 '16 at 10:29
2

avoid replying to obvious duplicates where the answers are richer and more detailed. – Jean-François Fabre Nov 08 '16 at 10:30

How to stop getting zeros returned in python?

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