I don't have a direct answer to your PostJSON question (just an idea: try to send JSONObjects, not JSONArrays - wrap the JSONArray) but I wanted to point out that there is a ThingWorx Machine Learning Extension (incorrectly called Coldlight Neuron Analytics - I'll ask to fix that) in the Marketplace that you can use for the basic interactions with TWX ML. It has services to create, configure and load datasets based on native TWX elements (mainly InfoTables).
Thank you very much for the prompt reply.
Wrapping the JSONArray and posting it by PostJSON, It didn't help.
I have already worked with Thingworx Machine Learning Extension. It has issues on configuring the dataset and uploading the data. Already got confirmation on these bugs from TS. So trying to create two services for them.
Thanks and regards,