WooCommerce - set image dimensions upon theme activation

functions.php

<?php
/**
 * Hook in on activation
 */

/**
 * Define image sizes
 */
function yourtheme_woocommerce_image_dimensions() {
	global $pagenow;
 
	if ( ! isset( $_GET['activated'] ) || $pagenow != 'themes.php' ) {
		return;
	}

  	$catalog = array(
		'width' 	=> '400',	// px
		'height'	=> '400',	// px
		'crop'		=> 1 		// true
	);

	$single = array(
		'width' 	=> '600',	// px
		'height'	=> '600',	// px
		'crop'		=> 1 		// true
	);

	$thumbnail = array(
		'width' 	=> '120',	// px
		'height'	=> '120',	// px
		'crop'		=> 0 		// false
	);

	// Image sizes
	update_option( 'shop_catalog_image_size', $catalog ); 		// Product category thumbs
	update_option( 'shop_single_image_size', $single ); 		// Single product image
	update_option( 'shop_thumbnail_image_size', $thumbnail ); 	// Image gallery thumbs
}

add_action( 'after_switch_theme', 'yourtheme_woocommerce_image_dimensions', 1 );

It's not working in my theme :(

i put this into my theme but not effect in next install with new database?

This works only on activation of the theme, so you can either trick it by changing theme and going back, or just using:

    $catalog = array(
        'width'     => '400',   // px
        'height'    => '400',   // px
        'crop'      => 1        // true
    );
    $single = array(
        'width'     => '600',   // px
        'height'    => '600',   // px
        'crop'      => 1        // true
    );
    $thumbnail = array(
        'width'     => '120',   // px
        'height'    => '120',   // px
        'crop'      => 0        // false
    );
    // Image sizes
    update_option( 'shop_catalog_image_size', $catalog );       // Product category thumbs
    update_option( 'shop_single_image_size', $single );         // Single product image
    update_option( 'shop_thumbnail_image_size', $thumbnail );   // Image gallery thumbs

At the bottom of functions.php and it worked fine, although this works for my theme because I don't want people to be able to change the sizes.

Hello guys. Is there anyway i can change thumbnail crop position by using this?