FROM (df1 JOIN df2 ON df1.census_tract = df2.census_tract AND df1.county_code =
df2.county_code)
JOIN df3 ON df1.census_tract = df3.census_tract AND df1.county_code = df3.county_code')
```
Key variables controlled in the model: time data collected, if it is a university zone.
(12) ![The second git log](figure/git_log2.png)
![Merge branch to main](figure/git_merge.png)
To reset the respository, type: git reset -hard(branch code)
(13)
```{R}
lr <- lm(estmtd_home_val_sum~employee_size_sum+sales_volume_sum+household_wealth_sum+
household_income_sum+percent, data=df)
summary(lr)
```
![Fit result](figure/fit.png)
Fit the data with a linear regression model where the response is the home value summation in a tract and the variables are: (1) employee size summation in a tract; (2) sales volume summation in a tract; (3) household wealth summation in a tract; (4) household income summation in a tract; (5) percent of white race household in a tract.
The result shows the property evaluation doesn't exhibit racial bias in the state of Alabama with p-value = 0.31 > 0.05. When total home value increases by 1 unit (\$1000), total employee size will increase by 2.93 when controlling other variables; total sales volume (annual revenues) will increase by 0.037 unit when holding other variables unchanged; total household wealth will increase by 0.058 unit (\$1000) when keeping other variables; and total household income will increase 1.3 units (\$1000) when controlling other variables.
Q2
(1) A cluster is composed of many servers connected to each other and each server is seen as a node. The core is the part of processor that does the computations and a node has many cores.
The login node is for preparing to run a program. The compute node is for running the program.
(2) ![SLURM script example](figure/SLURM.png)
(3) ![Create a symbolic link from home directory to scratch directory](figure/scratch.png)
The full path is: /scratch/stats506s001f22_class_root/stats506s001f22_class/yangyus
If the link is deleted, the original directory is not affected.