After some difficulty, I was able to create a histogram. (When I called for CoDap to “fuse the dots,” I was refused and given an error code.) To wit,
“An error has occurred that may affect how this program behaves. You may wish to reload this page after you save your work. (Error: Cannot read property ‘valueToBinNumber’ of null)”
But, apparently I held my mouth just right one time . . . and then it worked.
I think it’s related to this, however. I wanted the vertical axis to provide relative frequencies, instead of “counts.”
Oddly, the ruler has a “counts” and “percent” option, but after I fuse the dots into bars — only “counts” remains. If I set “percent” beforehand, I get the above error message when I fuse the dots.