session-vectors.qmd

---
title: "Introduction to R and Rstudio"
subtitle: "Session  - Vectors"
---

## Vectors

```{r}
#| echo: false
#| label: "libs"
#| include: false
library(readr)
library(dplyr)

```

```{r}
#| echo: false
#| label: "load-data"
#| eval: false
beds_data <- read_csv(url("https://raw.githubusercontent.com/nhs-r-community/intro_r_data/main/beds_data.csv"), 
                      col_types = cols(date = col_date(format = "%d/%m/%Y")), 
                      skip = 3)
```

Are a type of data format in R but may be familiar

You can create a vector with function: `c()` for `concatenate/combine`. In SQL it would just be `()` with no c

```{r}
c(100, 80, 200)

c("beds", "staff", "patients")

# Mixing strings (characters) and numeric values results in all being strings
c("beds", 80, "patients") 
```

## Looking for more than one string

```{r}

c("Bradford District Care", "Bradford District Care Trust")

# can be made into an object
org_lookup <- c("Bradford District Care", "Bradford District Care Trust")
```

## Using in `filter()`

Filter by org_name IN the lookup list.

```{r }
#| code-line-numbers: "2"
beds_data |> 
  filter(org_name %in% org_lookup) 
```

Code would look like this in SQL

```{sql}
SELECT *
FROM Table
WHERE Colm IN ('Bradford District Care', 'Bradford District Care Trust')

```

## Negative or NOT IN

Filter by org_name NOT IN the lookup list.

```{r }
#| code-line-numbers: "2"
beds_data |> 
  filter(!org_name %in% org_lookup)
```

In SQL

```{sql}
SELECT *
FROM Table
WHERE Colm NOT IN ('Bradford District Care', 'Bradford District Care Trust')
```

## End session