# Case study – Tornado plot

There is a known gender difference in the age of schizophrenia onset. It is clearly visible in FinnGen data as well. The following R code will produce a tornado plot visualizing this difference in FinnGen population.

```r
# get FINNGENID and the age at first schizophrenia diagnose
sql<-paste0(
  "SELECT FINNGENID, MIN(AGE) AS ENTRY_AGE ",
  "FROM finngen_r10_service_sector_detailed_longitudinal_v2.",
    "sandbox_tools_r10.",
    "finngen_r10_endpoint_cohorts_v1 ",
  "WHERE ENDPOINT = 'F5_SCHZPHR' ",
  "GROUP BY FINNGENID " 
)

tb <- bq_project_query(projectid, sql)
df <- bq_table_download(tb) 

# get the gender from baseline
df <- left_join(df, df_baseline, by = "FINNGENID") 

df <- df %>%
  mutate(AGE = round(ENTRY_AGE)) %>%
  mutate(AGE = cut(AGE, breaks = seq(from = 0, to = 110, by = 5))) %>%
  select(FINNGENID, AGE, SEX) %>%
  group_by(AGE,SEX) %>%
  summarise(N = n(), .groups = "drop") %>% 
  mutate(AGE = fct_drop(AGE)) %>% 
  drop_na(AGE,SEX) %>% 
  complete(AGE, SEX, fill = list(N = 0)) %>% 
  group_by(SEX) %>%
  mutate(ALL = sum(N)) %>%
  ungroup() %>%
  mutate(PR = round(100 * N/ALL, 3)) %>% 
  mutate(PR = ifelse(SEX == 'female', PR, -PR))

ggplot(df, aes(x = PR, y = AGE, fill = SEX)) +
  geom_bar(data = subset(df, SEX == 'female'), stat = "identity") +
  geom_bar(data = subset(df, SEX == 'male'), stat = "identity")+
  scale_x_continuous(labels = abs, limits = c(-15,15)) +
  theme_bw() +
  labs(
    title = "Schizophrenia age of onset",
    x = "Percentage",
    y = "Age group",
    fill = "Gender"
  )

```

<figure><img src="/files/UHY7yvyJWOWP5wH8ujOn" alt=""><figcaption></figcaption></figure>

**Location of the script's in the Sandbox**

Below is a path to the R Markdown file in Sandbox. This R Markdown file can be converted to an html page using "knit" command. The R Markdown is a plain text file, so you can copy code snippets that you need.

`/finngen/library-green/scripts/code_snippets/BigQuery_Templates_release.Rmd`


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.finngen.fi/working-in-the-sandbox/which-tools-are-available/miscellaneous-helper-scripts-tools/bigquery-connection-r/case-study-tornado-plot.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.