Get metrics from Facebook Ads API

I am not able get the below metrics from Facebook API. How can I calculate the these metrics, which appear in Facebook's own ads interface, from the Facebook开发者_如何学运维 Ads API:

• Reach
• Social reach
• Frequency,
• CPC,
• CPM.

When you have the Ad group ID, you have to issue an API call: https://graph.facebook.com/<AD-GROUP_ID>/stats

Then you get answer like this:

{
  "id": "<AD-GROUP_ID>/stats/0/.....", 
  "impressions": 31, 
  "clicks": 0, 
  "spent": 0, 
  "social_impressions": 0, 
  "social_clicks": 0, 
  "social_spent": 0, 
  "unique_impressions": 0, 
  "social_unique_impressions": 0, 
  "unique_clicks": 0, 
  "social_unique_clicks": 0, 
  "actions": 0, 
  "connections": 0, 
  "adgroup_id": 6003713142141, 
  "start_time": null, 
  "end_time": "2011-11-07T06:43:21+0000"
}

To calculate the fields in the Facebook frontend:

'Reach' = unique_impressions
'Social Reach' = is called social_unique_impressions.
'Frequency' = impressions / unique_impressions
'CPC' = spent / clicks
'CPM' = (spent * 1000) / impressions