[FIXED] How to average two (or multiple histograms) with R

Issue

Could someone tell me how to average two histograms with R?

I came across the HistogramTools package and the AddHistograms function:

h1<-hist(na.omit(a[,1]),breaks = 100,plot=F)
h2<-hist(na.omit(a[,2]),breaks = 100,plot=F)
> AddHistograms(h1,h2)
Error in .AddManyHistograms(x, main = main) : 
  Histograms must have identical breakpoints for this operation.

but I always have the same error Histograms must have identical breakpoints for this operation? can someone explain why? I am guessing is that a[,1] and a[,2] are not the same length, same with the outputs of h1 and h2 (i.e. I don't have the same length for "breaks","mids","counts" between h1 and h2).

Could you tell me how to average my two histograms using this function or anything else with R?

Solution

Follow the steps below:

1. Create h1 and h2,
2. combine and sort the breaks vectors,
3. keep the unique values
4. and add the histograms.

With the (not reproducible) example in the question,

h1 <- hist(na.omit(a[,1]), plot = FALSE)
h2 <- hist(na.omit(a[,2]), plot = FALSE)

brks <- sort(c(h1$breaks, h2$breaks))
brks <- unique(brks)

h1 <- hist(na.omit(a[,1]), breaks = brks, plot = FALSE)
h2 <- hist(na.omit(a[,2]), breaks = brks, plot = FALSE)

h12 <- AddHistograms(h1, h2)
plot(h12)

Note also that na.omit is not really needed, hist will discard them anyhow.

Answered By - Rui Barradas

Answer Checked By - Willingham (PHPFixing Volunteer)