graph add vertical line using value in macro variable

[Kim Colyvas]

I am using Stata 13

I want to develop code to add a single vertical line on a graph using a value obtained from a dataset rather than having to hard code the position of the line. This would make the code general.

I thought I would do it by saving a value from the data set in a macro variable and use the macro variable to substitute into the xline graph option.

The code below fails to add a line when I use the macro variable but works when hard coded.

Is there something else I should be doing to get this to work?

clear

set obs 12

gen y = 42

gen time = _n/y*100

line y time, xline(7)

global time1 7

macro list

line y time, xline(`time1')

Thanks,

Kim

[Red Owl]

You greated a global macro rather than than a local macro for time1.

This should work for you.

line y time, xline($time1)

Red Owl
Stata/IC 16.0 (Windows 10, 64-bit)

[Kim Colyvas]

Great - it works!
Use $time1 for a global macro.

Also I took note of your aside about local vs global macro and experimented and found that
local time2 20
line y time, xline(`time2')
also worked. So for a local macro we use `time2'.
I think in testing this wasn't working for me because I was running the code in parts, i.e. execute the macro command and stop to confirm it had worked and then run the plotting command with a separate execute command. When I selected both lines in my do file and executed them together it worked.

Thank you for your help,
I had spent a lot of time on this,
Kim