I need to generate 625 different numbers between 1e-321 and 1e-200. However, when I use seq() function, it doesn't give me a good distribution.

seq(from = 1e-321, to = 1e-200, by = ((1e-200 - 1e-321)/624))

gives an output like this where only one value has -322 power (which is out of my range) and all others are in 1e-203, 1e-201, 1e-200 range.

I need an output, so all 625 numbers would be evenly distributed across the given range.

CodePudding user response：

It sounds, as @merv noted, that you want your numbers to be spaced evenly in log space, eg with a similar number in each order of magnitude. Here's one way. 1e-321 is the same as 10^-321, so we could raise 10 to a series of exponents which themselves are evenly spaced.

10^seq(from = -321, to = -200, length.out = 625)

You'll note the output has 5 or 6 values for each order of magnitude, with each value about 1.563x the prior value. 1.563^624 (b/c there are 624 changes between 625 numbers) is approx. e 121 which is what we want -- 1e-200 is 121 orders of magnitude larger than 1e-321.