Macro Command Reference
sortx <BUFFER>
This function sorts the data by X values. 
BUFFER
a list of one or more data buffers. Possible values are:
all | all buffers in the document | 
visible | visible buffers in the document | 
hidden | hidden buffers in the document | 
none | no buffer | 
b1,b2,b3,...,bn | a list of buffers where the arguments may be math expressions. | 
bs..be | buffers from bs to be |