Customizing the WordPress Query

wps_change_posts_per_page_in_grid.php

<?php
 
add_action( 'pre_get_posts', 'wps_change_posts_per_page_in_grid' );
/**
 * Change Posts Per Page
 * 
 * @author Bill Erickson
 * @author Travis Smith
 * @link http://www.billerickson.net/customize-the-wordpress-query/
 * @link http://wpsmith.net/2013/genesis/genesis-grid-loop-in-genesis-1-9/
 * @param object $query WP Query data
 *
 */
function wps_change_posts_per_page_in_grid( $query ) {
  
	global $wp_the_query;
	if( $query->is_main_query() && wps_is_doing_grid_loop() ) {
		$query->set( 'posts_per_page', '15' );
	}
 
}

wps_exclude_cat_in_grid.php

<?php
 
add_action( 'pre_get_posts', 'wps_exclude_cat_in_grid' );
/**
 * Exclude Category from Grid
 * 
 * @author Bill Erickson
 * @author Travis Smith
 * @link http://www.billerickson.net/customize-the-wordpress-query/
 * @link http://wpsmith.net/2013/genesis/genesis-grid-loop-in-genesis-1-9/
 * @param object $query WP Query data
 *
 */
function wps_exclude_cat_in_grid( $query ) {
  
	if( $query->is_main_query() && wps_is_doing_grid_loop() ) {
		$query->set( 'cat', '-1,-2' );
	}
 
}

wps_include_cat_in_grid.php

<?php
 
add_action( 'pre_get_posts', 'wps_include_cat_in_grid' );
/**
 * Limit Query to one Category
 * 
 * @author Bill Erickson
 * @author Travis Smith
 * @link http://www.billerickson.net/customize-the-wordpress-query/
 * @link http://wpsmith.net/2013/genesis/genesis-grid-loop-in-genesis-1-9/
 * @param object $query WP Query data
 *
 */
function wps_include_cat_in_grid( $query ) {
  
  if( $query->is_main_query() && wps_is_doing_grid_loop() ) {
		$query->set( 'cat', '4' );
	}
 
}

wps_is_doing_grid_loop.php

<?php

/**
 * Possibly amend the loop.
 * 
 * Specify the conditions under which the grid loop should be used.
 *
 * @author Bill Erickson
 * @author Gary Jones
 * @author Travis Smith
 * @link   http://code.garyjones.co.uk/genesis-grid-loop-advanced/
 * @link   http://wpsmith.net/2013/genesis/genesis-grid-loop-in-genesis-1-9/
 *
 * @return boolean Return true of doing the grid loop, false if not. 
 */
function wps_is_doing_grid_loop() {
 
  // Amend this conditional to pick where this grid looping occurs.
	// This says to use the grid loop everywhere except single posts,
	// single pages and single attachments.
	return ( ! is_singular() );
 
}