Data Manipulation in R.Rmd

---
title: "Data Manipulation in R"
date: "19/08/2021"
output: html_document
---
#### Name : Sara Kulkarni
#### Reg. no : 19BCE1567

Obtain a data frame called “newsurvey” by removing all ‘na’ values in “survey” data of MASS package to do the following:

```{r}
library(MASS)
data(survey)
any(is.na(survey))
```


```{r}
sum(is.na(survey))
```


```{r}
newsurvey <- na.omit(survey)
nrow(newsurvey)
```

1. Install the dplyr package and import it.

```{r}
library(dplyr)
```

2. Filter the bottom 5 male left handers.

```{r}
newsurvey %>%
  filter(W.Hnd=="Left") %>%
  tail(5)
```

3. Display all male right handers who keep left on top while clapping.

```{r}
newsurvey %>%
  filter(Sex=="Male",W.Hnd=="Right",Clap=="Left")
```

4. Display random 3 students under each category of exercise.

```{r}
newsurvey %>%
  group_by(Exer) %>%
  slice_sample(n=3)
```

5. Display random 6 rows of gender, age and writing hand columns of the students.

```{r}
newsurvey %>%
  dplyr::select(Sex,Age,W.Hnd) %>%
  slice_sample(n=6)
```

6. Display random 50% of the rows of age, pulse rate and writing hand span of male right handers.
```{r}
newsurvey %>%
  filter(Sex=="Male",W.Hnd=="Right") %>%
  dplyr::select(Age,Pulse,W.Hnd) %>%
  sample_frac(0.5)
```

7. Arrange all female right handers according to descending order of their heights.

```{r}
newsurvey %>%
  filter(Sex=="Female",W.Hnd=="Right") %>%
  arrange(desc(Height))
```

8. Introduce a new column hand_span which contains the value as sum of span of writing hand and non-writing hand and display it along with gender, writing hand and non-writing hand span.
```{r}
newsurvey %>%
  mutate(hand_span=Wr.Hnd+NW.Hnd) %>%
  dplyr::select(Sex,Wr.Hnd,NW.Hnd,hand_span)
```

9. Display the median writing span of male and female left handers.

```{r}
newsurvey %>%
  filter(W.Hnd=="Left") %>%
  group_by(Sex) %>%
summarize(median=median(Wr.Hnd))
```

10. Find the minimum pulse rate of male left and right handers.

```{r}
m=filter(newsurvey, Sex=="Male", W.Hnd == "Left")
m1=filter(newsurvey, Sex=="Male", W.Hnd == "Right")
min(m[,"Pulse"])
```

```{r}
min(m1[,"Pulse"])
```


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