Data visualization

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# Data visualization
## How to learn coding
### Ben Baumer
### SDS 192</br>Sep 16, 2020</br>(<a href="http://beanumber.github.io/sds192/lectures/mdsr_viz_07-coding.html" class="uri">http://beanumber.github.io/sds192/lectures/mdsr_viz_07-coding.html</a>)

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## About Googling...

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![](https://media.giphy.com/media/DWlJeG2pGW4jC/giphy.gif)

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- use `ggplot2` in your searches

- use [`ggplot2` tag on Stack Overflow](https://stackoverflow.com/questions/tagged/ggplot2)

- beware of base R and `lattice` solutions
    - ~~`plot()`~~
    - ~~`xyplot()`~~

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## Don't copy-and-paste code

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- Coding is a [form of expression](https://femgineer.com/2012/09/software-engineering-another-form-of-self-expression/)

- It's like taking notes

- Write it yourself from scratch

- **Don't submit code that you don't understand**

- See Syllabus for [Collaboration policy](../syllabus.html#policies)

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![](https://media.giphy.com/media/XcqjhVYVCgNgs/giphy.gif)

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> "Imagine learning to write by copying-and-pasting sentences!" (student in SDS 410)

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## Bad filenames

- Problems: 
    - spaces and special characters in filenames are bad
    - file extensions are important

- Solutions:
    - use underscores (`_`) and/or dashes (`-`)
    - use `.Rmd`

- Jenny Bryan on [naming things](https://speakerdeck.com/jennybc/how-to-name-files?slide=3)

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background-image: url(http://hackwrite.com/img/file-name-guides.png)

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## Ongoing confusion

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R session (active)

- Console pane
- interactive
- full benefit of RStudio IDE
- Environment/History pane
- Files/Plots/Packages/Help pane

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R session (passive)

- R Markdown pane
- **sequential**
- invisible
- created when you Knit
- creates HTML output

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## When you need to clean up...

- Broom icon in Environment to sweep away objects

- Run all chunks above
    - Middle triangle over bar, next to arrow
    - `Ctrl + Alt + P`

- `Session` -> `Restart R`

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## Navigating R help

- Will come with experience

- R help:
    - rigorously formatted
    - often incomplete
    - often complete but inscrutable
    - examples can be hit-or-miss
    - argument descriptions are usually good