COCO api evaluation for subset of classes

I refer to this page (http://www.programmersought.com/article/3065285708/)

cocoEval = COCOeval(cocoGt,cocoDt,annType)
coco_eval.params.catIds = [1] #person id : 1
cocoEval.params.imgIds = imgIds   
cocoEval.evaluate()  
cocoEval.accumulate()  
cocoEval.summarize() 

Additionaly, I modified cocoapi/PythonAPI/pycocotools/cocoeval.py to calculate AP for each category.
line 458-464 in https://github.com/kimyoon-young/centerNet-deep-sort/blob/master/tools/cocoeval.py

The result is like below.

category : 0 : 0.410733757610904 #person AP
category : 1 : 0.20226150054237374 #bird AP
....
category : 79 : 0.04993736566987926
(all categories) mAP : 0.27999824034118914 # my results
Average Precision (AP) @[ IoU=0.50:0.95 | area= all | maxDets=100 ] = 0.280 #original