xlabel does not work for restricting the x-axis

[James Sonela]

Hi,

I am plotting the mean of treatment and control groups. My data period (and naturally, my x-axis) is long so I would like to focus on the middle section of my graph and for this end, I use xlabel but it does not work.

I am working with quarterly data (qdate: 2016q3 etc.). I already formatted this date successfully via %tq and set my main time variable with xtset. I run the following code:

scatter std_mean_y1  qdate, connect(l) sort || scatter std_mean_y0 qdate, sort connect(l) xlabel(215(1)225)

This does not work. It only puts the labels in the x-axis but it does not restrict the axis.

Start date: 2011q3 (x-axis value: 206)
End date: 2019q4 (x-axis value: 239)

My bonus question is to how to plot a fitting line for each of the variables before and after a cutoff date (pre and post intervention periods). How can I accomplish it with lfit?

[Clyde Schechter]

It [xlabel()] only puts the labels in the x-axis but it does not restrict the axis.

This is a commonly encountered difficulty. I'm not sure why, since the help and PDF documentation state very clearly that this is exactly what -xlabel()- does:

ylabel(rule_or_values), xlabel(rule_or_values), tlabel(rule_or_values), and
zlabel(rule_or_values) specify the major values to be labeled and ticked along the
axis. For instance, to label the values 0, 5, 10, ..., 25 along the x axis, specify
xlabel(0(5)25). If the t axis has the %tm format, tlabel(1999m1(1)1999m12) will
label all the months in 1999.

It say nothing at all about defining the extent of the axis. To restrict an axis, you have to add an -if- qualifier to the graph command. So what you want is:

scatter std_mean_y1 qdate if inrange(qdate, 215, 225), connect(l) sort || scatter std_mean_y0 qdate if inrange(qdate(215, 225), sort connect(l) xlabel(215(1)225)

The same will apply to -lfit-: use an -if- clause to restrict the range of qdate.

[James Sonela]

This is a commonly encountered difficulty. I'm not sure why, since the help and PDF documentation state very clearly that this is exactly what -xlabel()- does:

It say nothing at all about defining the extent of the axis. To restrict an axis, you have to add an -if- qualifier to the graph command. So what you want is:

scatter std_mean_y1 qdate if inrange(qdate, 215, 225), connect(l) sort || scatter std_mean_y0 qdate if inrange(qdate(215, 225), sort connect(l) xlabel(215(1)225)

The same will apply to -lfit-: use an -if- clause to restrict the range of qdate.

Many thanks Clyde! I am now able to obtain the graph. However, I am still having troubles in putting linefits for each variable before and after a cutoff date (for instance; 220)

[Clyde Schechter]

As there is no example data to work with, this code is untested and may not work, but it should point you in the right direction.

lfit std_mean_y1 qdate if inrange(qdate, 215, 220) || lfit std_mean_y1 qdate if inrange(qdate, 220, 225)