Default [Q] Resizing active partitions

Is it possible to resize active partitions/
I am running Stock JB on sytem1 and ParanoidAndroid 4.3 on ssytem 2 (this is my primary system). Prior to ROM flashing I created (3) 1GB partitions for each system. Now my Data partition for system 2 is at 100MB even after I moved every app I could to the SD card. Every thread I looked at said 1GB was more than enough for a data partition so I cannot understand how I've run out of space. Perhaps I am not using the partition structures correctly. Anyway, I was hoping to resize an active partition the same way I have with Partition Magic when resizing a Windows drive partition. Thanks for any replies.