Generate public SSH key from private key

Suppose I have a SSH keys pair, but I’ve deleted the public key. I have the private key only. How can I regenerate public key from private key ?

man ssh-keygen says:

-y      This option will read a private OpenSSH format file and print an
         OpenSSH public key to stdout.

The following command will generate a public key for you:

ssh-keygen -f ~/.ssh/id_rsa -y > ~/.ssh/id_rsa.pub