using CMS.TreeEngine;

using CMS.CMSHelper;

int nodeId = 241;

double rating = 0.5f;

// Get the document

TreeProvider tree = new TreeProvider(CMSContext.CurrentUser);

CMS.TreeEngine.TreeNode node = tree.SelectSingleNode(nodeId, CMSContext.PreferredCultureCode);

// Add rating

// If the 3rd parameter is true, information that the document has been rated is stored in a cookie. It is possible to check if the user rated the document.

TreeProvider.AddRating(node, rating, false);