### Problem - [x] d_to_tth - [x] tth_to_d - [x] d_to_q - [x] q_to_d - [x] get_angle_index - [ ] scale_to - [x] on x_type <!-- For a bug report, please copy and paste any error messages from the application or command-line here. For a feature request, please state how the new functionality could benefit the community. --> ### Proposed solution
