I was trying to create my own dataset from the digitized graph from Hollomon, J. H. Tensile Stress-Strain Curves of a 70-30 Brass. (1944) that was also used by you, but when I upload my own dataset, it says that "The entire dataset is visualized using a scatter plot". I would like to look at your default dataset to understand how should I create my own datasets. 

Thank you.