---
title: "R Notebook"
output: html_notebook
---
```{r}
plik <- read_excel('rzeczy/test.xlsx', sheet = 'data')
plik
```
```{r}
#1
plik %>%
  select(fc11) %>%
  filter(fc11==2) %>%
  dplyr::count()
```
```{r}
#2
summarise(filter(plik, fc11==2), mean(age))
```
```{r}
#3
summarise(
  filter(plik, sex==1),
  mean(fp65), min(fp65), max(fp65), sd(fp65), median(fp65)
)
```
```{r}
#4
cbind(
plik %>%
  filter(fp29==1) %>%
  select(class) %>%
  count(),
plik %>%
  filter(fp29==2) %>%
  select(class) %>%
  count()
)
```
```{r}

#5
plik %>%
  dplyr::group_by(sex) %>%
  filter(age<=35) %>%
  select(sex, age) %>%
  dplyr::count(sex)
```
```{r}
#7
dane7 <- plik %>%
  filter(class==1, sex==1) %>%
  select(fp55, fp56)
cor(dane7, method="pearson")
```
```{r}
#8
dane8 <- plik %>%
  filter(sex==2)
quantile(dane8$fp55)
```
```{r}
#9
plik
f9 <- function(plik) {
  a <- ggplot(plik, aes(x=class))+ geom_bar()
  b <- ggplot(plik, aes(x=fc11))+ geom_bar()
  return (list(a,b))
}
f9(plik)
```
```{r}
#10
func <- function(r) {
  return (c((4*pi*r^2), (4/3*pi*r^3)))
}
func(2)
```
```{r}
#11
A = matrix(c(19, -13, 30, 3, -35, 56), nrow=3, byrow=TRUE)
B = matrix(c(-5, -1, -30, -45, 35, 56), nrow=3, byrow=TRUE)
4*A-2*B
solve(t(A)%*%B)
```