How to avoid line breaking after subsection in Memoir?

Question

\documentclass{memoir}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{bbm}
\usepackage{graphicx}
\usepackage{epsfig}
\usepackage[all]{xy}

\setcounter{chapter}{0}
\setcounter{secnumdepth}{3}
\renewcommand*\thesection{\arabic{section}}
\renewcommand*\thesubsection{\arabic{section}.\arabic{subsection}}

This gives me a "line" break after section, subsection, subsubsection. I want to keep the "line" break after section, but for subsections and subsubsections I want the text to continue on the same line right after the heading.

Answer 1

Add the following code to the preamble:

\setaftersubsecskip{-1em}
\setaftersubsubsecskip{-1em}

(adjust the spacing, but it must be negative).

Note: the package epsfig is obsolete and should not be used in new documents.