Find the index of negative multiplying of two vectors in R -


i have 2 vectors , want find index of multipling of these 2 vectors gets negative , a[index]is negative , b[index] positive. how can find indexin r?

    = c(1, -1, 2, 3, 4)     b  =c(-1, 3, 5, 4, -5)     c =  a*b

i have tried not desire result:

    > which( c <= 0)     [1] 1 2 5

the final result should index = 1 , 5.

after reading question 10 times, think regarded answer 2 simon0101 says.

which( < 0 & b >= 0 & c < 0)

please review zour question or expected result.


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