Show featured image (post thumbnail) on single posts

featured_image_on_single_post.php

<?php

// Show featured image on single posts
add_action( 'genesis_before_entry_content', 'child_featured_post_image', 8 );
function child_featured_post_image() {
	if ( ! is_singular( 'post' ) )  return;
	
	the_post_thumbnail('post-image');
}

// OR THIS ONE

// Show featured image on single posts
add_action( 'genesis_before_entry_content', 'child_featured_post_image', 8 );
function child_featured_post_image() {
	
	if ( ! is_singular( 'post' ) )
		return;
	
	$img = genesis_get_image( array( 'format' => 'html', 'size' => genesis_get_option( 'image_size' ), 'attr' => array( 'class' => 'post-image' ) ) );
	printf( '<a href="%s" title="%s">%s</a>', get_permalink(), the_title_attribute( 'echo=0' ), $img );
	
}