InfoPath Dev

Hi All, i've just added calculation field in infopath form 2013 that already has existing item previously. when i publish the changes, the existing item doesn't shown the value of the calculation. may i know how can we refresh the existing item so the new calculation fied that i've just added will be shown on sharepoint? thanks for you help :)

I am guessing that this is a library form, published to a library. Your existing items won't have the new field present. If you download one and open the XML in a text editor, you'll see that the new field isn't there. You will probably have to open and resave each existing item. Try with one and see if the data shows up. If it doesn't you may also need to change the setting in the InfoPath form versioning to update existing items.