---
title: "Homework 5"
date: "November 27, 2019"
author: "Write your name here"
number: STUDENT_NUMBER
subtitle: "Computing in Molecular Biology and Genetics I. Istanbul University."
output: 
  html_document: 
    number_sections: yes
    self_contained: no
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```


1. Download the file [`midterm.txt`](/static/world2017.txt), store it in your computer, and read it into a data frame called `world`. Show `summary(world)`.
```{r q1}
# write here
```

2. Show the first 20 lines of `world` in a nice way, using the `kable` command. There may be some *warnings*, but they are not important.
```{r q2, warning=FALSE}
# write here
```

3. Draw this
```{r q3}
# write here
```

4. Draw this
```{r q4}
# write here
```

5. Draw this
```{r q5}
# write here
```

6. The last graphic is hard to read, since most of the countries have small income and small population. We can see better using the option `log="xy"`. Redraw the last plot using the new option.
```{r q6}
# write here
```

7. This time the symbol color depends on the region
```{r q7}
# write here
```

8. Now we want to change the symbol size depending on the country's area. The formula for the symbol size should be `3*sqrt(area/max(area)))`
```{r q8}
# write here
```


9. Now we will add decoration. Repeat the previous command, and then use the commands `legend()` and `title()` to produce this image
```{r q9}
# write here
```