A data set of motion tasen from a smart watch whilst the subject writes the 26 letters of the alphabet created at UCR (we believe). 
There are 150 train cases and 850 test cases. The three dimensions are the three x,y and z accelerometer values. 



[1] M. Shokoohi-YektaEmail B. HuHongxia J. Wang and E Keogh (2017) Generalizing DTW to the multi-dimensional case requires an adaptive approach.
Data Mining and Knowledge Discovery (31) 1, pp 131