## How do I plot a curve from a file?

The make_figure and add_curve commands can plot data from a file (in both FITS binary and ASCII formats).

1. Two columns: A set of (x,y) points.

make_figure("file.lis[cols x,y]")


This will plot up columns x and y from the file file.lis.

2. Three columns: A set of (x,y) points with symmetric errors on y.

make_figure("file.lis[cols x,y,dy]")


This will plot up columns x and y from the file file.lis, and draw symmetric error bars whose length is given by the dy column. The dy values should be >= 0.

3. Four columns: A set of (x,y) points with asymmetric errors on y.

make_figure("file.lis[cols x,y,dylo,dyhi]")