javascript - D3.js: Exteding the y-axis without making any changes to the existing chart -

i learning d3.js , using code: http://bl.ocks.org/caged/6476579 changed data sets bit , occupy whole chart(the values quite closer , larger given example). want extend y axis(and reduce bar size).

things tried: in rect attr, changed attribute height height/2, changes height of rectangle size not values of y axis.

tried change range values of y axis [height,0] [height/2, 0], still no luck.

how achieve this? also, using "s" tickformat(not percentages in example)

you need edit y.domain fit data. so, edit line

y.domain([0, d3.max(data, function(d) { return d.frequency; })]); 

for example, make chart axis go 0 100%:

y.domain([0, 1]); // 0% 100%