## Example: GAUSS Sbreak procedure

This example follows the empirical application of Bai and Perron (2003). Below we use the **GAUSS** `sbreak` procedure to estimate breaks in the mean of the US expost real interest rate. The first step is to directly load the quarterly series of the three-month treasury bill provided in the file `real.dat`:

```
//Load TSMT library
library tsmt;
//Load y data
load y[] = real.dat;
//Specify regressors
//Time varying coefficients in z
z = ones(rows(y),1);
//No time invariant regressors
x = 0;
```

Next we declare and initialize the structural break control structure and set model specific parameters:

```
//Declare sbControl structure
struct sbControl sbc0;
//Initialize instance of structure
sbc0 = sbControlCreate();
```

Then we specify the model parameters:

```
//Number of regressors subject to change
sbc0.q = 1;
//Number of structural changes
sbc0.m = 5;
//Trimming percentage
sbc0.trim = 0.15;
//Minimum length of segment (h > p + q)
sbc0.h = 0;
//Print iteration output
sbc0.printOutput = 1;
//Maximum number of iterations
sbc0.maxIters = 40;
```

Finally we declare the output structure and call the `sbreak` procedure:

```
//Declare output structure
struct sbOut SBout;
//Estimate model
SBout = sbreak(y,z,x,sbc0);
```

Which prints out the following report.

```
Global optimization of structural change model
The model with 1 breaks has SSR : 644.99552
The dates of the breaks are:
79
The model with 2 breaks has SSR : 455.95018
The dates of the breaks are:
47
79
The model with 3 breaks has SSR : 445.18186
The dates of the breaks are:
24
47
79
The model with 4 breaks has SSR : 444.87975
The dates of the breaks are:
24
47
64
79
The model with 5 breaks has SSR : 449.63949
The dates of the breaks are:
16
31
47
64
79
```