---
tags: ECON30025, solutions, SAS
---

In-Tutorial Extensions (T1-4, W2-5)
===============

> [Link to all tutorials](/aAU_CJOdSq2wQtIm9MdyWA)

### T1: Intro to SAS
1. What is a SAS library? How do we define a library?

2. Whats the difference between Explorer and Contents Only views?

3. How do we subset our datasets?
- [SUBSETTING DATA IN SAS | SAS LEARNING MODULES](https://stats.idre.ucla.edu/sas/modules/ubsetting-data-in-sas/)
4. How can we use `PROC PRINT` to inspect parts of our datasets?

> [color=#ff0000] see [OBS= Data Set Option](http://support.sas.com/documentation/cdl/en/ledsoptsref/69751/HTML/default/viewer.htm#p0h5nwbig8mobbn1u0dwtdo0c0a0.htm)

PROC PRINT (obs=10 , firstobs=20);
    where VARIABLE lt 30;
run;

### T2: Data Visualisations
1. How does SAS handle misspellings?
* [See SAS: AUTOCORRECT System Option](https://documentation.sas.com/?docsetId=lesysoptsref&docsetTarget=p0mzulmnthqs2bn1cuqm5eqlvgi8.htm&docsetVersion=3.1&locale=en)

2. What does the `NOPRINT` option do? how do we remove it from `HISTOGRAM / normal()`? how to we add it to `PROC KDE`?
* [See PROC UNIVARIATE > HISTOGRAM Statement](http://support.sas.com/documentation/cdl/en/procstat/66703/HTML/default/viewer.htm#procstat_univariate_syntax09.htm)
* [See PROC KDE > UNIVAR statement](https://support.sas.com/documentation/cdl/en/statug/63962/HTML/default/viewer.htm#statug_kde_sect003.htm)

3. What does `NGRID` in `PROC KDE` control? How does this relate to the lecture notes on KDE?

### T3: PROC SQL
1. Rewrite Q2, 4, 7c in only `PROC SQL` or Base SAS `DATA/PROC` steps

2. What do the following statements do?
- `count(*)`
- `outobs=10`
- `format=comma12.2`
3. What's the difference between`run;` and `quit;`?

4. Other Resources via Google:
* [SQL joins](http://www.sql-join.com/sql-join-types)
* [SQL style guide](https://www.sqlstyle.guide)

### T4: Linear Algebra
1. Try to generate 3x3 matrix using rule $a_{ij} = i - j$

2. `PROC IML` vs `PROC REG`: Why might we use one over another?