R How to use which() with floating point values?

Question

I have run into the same problem as described at R which () function returns integer(0)

price = seq(4,7, by=0.0025)
allPrices = as.data.frame(price)
lookupP         


        

Answer 1

You can sapply over all the prices and apply the all.equal function to each one, to find the one that is TRUE

which(sapply(price, all.equal, lookupPrice) == TRUE)
# [1] 425