Convert getValues for loops to map and filter

Originally written for bulldo.gs — republished here with the canonical link pointing home.

I want to rewrite my getValues for loop using map and filter so the code is shorter, but I keep getting a parameter mismatch error when I try to write results back with setValues.

// Keep only rows where column A > 100, then write column B values

function filterAndRemap() {

var sheet = SpreadsheetApp.getActiveSheet();