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Random numbers

Random draws that stay put, and New random numbers to draw again.

rnd, runif, rnorm and the other r functions draw random numbers: rbinom, rpois, rexp, rgamma and one for each distribution. Each function gives its own vector of draws.

A worksheet's draws stay the same each time it calculates, so results don't jump about while you edit, and a saved sheet opens with the numbers it had. They come from the worksheet's seed. Reroll on the toolbar picks a new seed and draws everything again; undo goes back to the old numbers. A Mathcad worksheet brings its own seed with it.

dbinom(3,10,0.3)=0.267
pnorm(1.96,0,1)=0.975
qnorm(0.975,0,1)=1.96

Each distribution has four functions: d for the density or probability, p for the cumulative probability, q for its inverse and r for random numbers, as dnorm, pnorm, qnorm and rnorm. The Probability distributions group in the contents lists them all.