## Stata 15 help for cusum

```
[R] cusum -- Cusum plots and tests for binary variables

Syntax

cusum yvar xvar [if] [in] [, options]

options               Description
-------------------------------------------------------------------------
Main
generate(newvar)    save cumulative sum in newvar
yfit(fitvar)        calculate cumulative sum against fitvar
nograph             suppress the plot
nocalc              suppress cusum test statistics

Cusum plot
connect_options     affect the rendition of the plotted line

addplot(plot)       add plots to the generated graph

Y axis, X axis, Titles, Legend, Overall
twoway_options      any options other than by() documented in [G-3]
twoway_options
-------------------------------------------------------------------------

Statistics > Other > Quality control > Cusum plots and tests for binary
variables

Description

cusum graphs the cumulative sum (cusum) of a binary (0/1) variable, yvar,
against a (usually) continuous variable, xvar.

Options

+------+
----+ Main +-------------------------------------------------------------

generate(newvar) saves the cusum in newvar.

yfit(fitvar) calculates a cusum against fitvar, that is, the running sums
of the "residuals" fitvar minus yvar.  Typically, fitvar is the
predicted probability of a positive outcome obtained from a logistic
regression analysis.

nograph suppresses the plot.

nocalc suppresses calculation of the cusum test statistics.

+------------+
----+ Cusum plot +-------------------------------------------------------

connect_options affect the rendition of the plotted line; see [G-3]
connect_options.

+-----------+
----+ Add plots +--------------------------------------------------------

addplot(plot) provides a way to add other plots to the generated graph.

+-----------------------------------------+
----+ Y axis, X axis, Titles, Legend, Overall +--------------------------

twoway_options are any of the options documented in [G-3] twoway_options,
excluding by().  These include options for titling the graph (see
[G-3] title_options) and for saving the graph to disk (see [G-3]
saving_option).

Examples

Setup
. sysuse auto

Graph cumulative sum of foreign against weight
. cusum foreign weight

Save as above, but save the cumulative sum in variable cs
. cusum foreign weight, generate(cs)

Stored results

cusum stores the following in r():

Scalars
r(N)                number of observations
r(prop1)            proportion of positive outcomes
r(cusum1)           cusum
r(zl)               test (linear)
r(P_zl)             p-value for test (linear)