lecture_05.md

# Good coding habits
## naming folders and files

[Stanford file naming best practices](https://library.stanford.edu/research/data-management-services/data-best-practices/best-practices-file-naming)

1. Include information to distinguish file name e.g. project name, objective of function, name/initials, type of data, conditions, version of file, 
2. if using dates, use YYYYMMDD, so the computer organizes by year, then month, then day
3. avoid special characters e.g. !, #, \$, ...
4. avoid using spaces if not necessary, some programs consider a space as a break in code use dashes `-` or underscores `_` or CamelCase

## Commenting your code

Its important to comment your code to mention what a variable's units are, what the function is supposed to do, etc. 



```octave
function i=code(j)
    % Example of bad variable names and bad function name
    for w=1:j
        i(w)=w;
    end
end
```


```octave
help code
```

    'code' is a command-line function
    
     Example of bad variable names and bad function name
    
    
    Additional help for built-in functions and operators is
    available in the online version of the manual.  Use the command
    'doc <topic>' to search the manual index.
    
    Help and information about Octave is also available on the WWW
    at http://www.octave.org and via the help@octave.org
    mailing list.


## Choose variable names that describe the variable


```octave
function count_vector=counting_function(max_value)
    % Good variable names and better help documentation
    % 
    % counting function creates a vector from 1 to max_value where each index, i, is 
    % stored in each vector spot
    for i=1:max_value
        count_vector(i)=i; % set each element in count_vector to i
    end
end      
```


```octave
help counting_function
```

    'counting_function' is a command-line function
    
     Good variable names and better help documentation
     
     counting function creates a vector from 1 to max_value where each index, i, is 
     stored in each vector spot
    
    
    Additional help for built-in functions and operators is
    available in the online version of the manual.  Use the command
    'doc <topic>' to search the manual index.
    
    Help and information about Octave is also available on the WWW
    at http://www.octave.org and via the help@octave.org
    mailing list.


## Putting it all together

1. Clone your homework_1 to your computer
2. open Matlab (cli, jupyter or gui)
3. Change working directory to homework_1 *e.g.* Windows:`cd('C:\Users\rcc02007\Documents\Github\homework_1')`, Mac: `cd('/Users/rcc02007/Documents/Github/homework_1')`
4. You have already created your first script `myscript.m` (if not see lecture_4)
5. Run `>> my_script.m`
6. Create a new m-file called nitrogen_pressure.m
7. Create a function based upon the ideal gas law for nitrogen, Pv=RT
    1. R=0.2968 kJ/(kg-K)
    2. inputs to function are v (specific volume m^3/kg), and T, temperature (K)
    3. output is P, pressure (kPa)
8. Once the function works, commit the change to the repository (add a message, like 'added file nitrogen_pressure.m'
9. After file is 'committed', 'push' the changes to your github account

for the command-line git user, this is steps 8 and 9:

1. `$ git add *`
2. `$ git commit -m 'added file nitrogen_pressure.m'`
3. `$ git push -u origin master
    Username for 'https://github.uconn.edu':rcc02007 <enter>
    `
   


```octave

```