# 
## Overview

Profiling in R can be performed using the following two functions:

1. `Rprof`
2. `summaryRprof`


## The `Rprof` function

The `Rprof` function records the call stack to the specified file every interval of seconds. It is also used to start and stop the profiling operation.

## Syntax

```
Rprof(filename = "Rprof.out", append = FALSE, interval = 0.02)
```

## Parameters

- `filename`: This is a file to be used for recording the profiling information.
- `append`: This is a boolean field that indicates whether the profiling information is appended to the existing file or be overwritten.
- `interval`: The time elapsed between the two consecutive samples. The default value is 20 milliseconds.

## The `summaryRprof` function

The `summaryRprof` function is used to summarize the information given by the `Rprof` function.

## Syntax

```
summaryRprof(filename = "Rprof.out")
```

## Parameter

- `filename`: This is a  `Rprof` function output file.

## Return value

The function returns the following summary statistics:

| Metric  | Description  |
| - | - |
| by.self  | A DataFrame of time spent in the executing function alone  |
| by.total  | A DataFrame of total time spent in the function and its callees  |
| sample.interval | The sampling time interval (Refer `interval` parameter of `Rprof` function)  |
| sampling.time  | The total time spent in profiling the run  |

## Code example
Let's look at the code below:

Rprof(tmp <- tempfile())
n = 15
if(n<=0){
    print("Invalid n value")
}else{
    fibo_list <- numeric(n)
    fibo_list[1] <- 1
    fibo_list[2] <- 1
    print(paste("The first",n," fibonacci numbers are as follows:"))
    if(n == 1) print(fibo_list[1])
    else if(n == 2) print(fibo_list)
    else{
        for (i in 3:10) fibo_list[i] <- fibo_list[i - 1] + fibo_list[i - 2]
        print(fibo_list)
    }
}
Rprof(NULL)
summaryRprof(tmp)

# 
## Code explanation

- **Line 1**: We invoke the `Rprof()` function with a temporary file.
- **Lines 2-16**: We have defined the logic for finding the first `n` numbers in the Fibonacci sequence.
- **Line 17**: We stop the profiling by invoking `Rprof(NULL)`. 
- **Line 18**: We obtain he profiling summary by invoking the `summaryRprof()` function.

Profiling code in R

Profiling in R uses Rprof to record call stacks and summaryRprof to summarize profiling data.

Metric	Description
by.self	A DataFrame of time spent in the executing function alone
by.total	A DataFrame of total time spent in the function and its callees
sample.interval	The sampling time interval (Refer `interval` parameter of `Rprof` function)
sampling.time	The total time spent in profiling the run

Profiling code in R

Overview

The Rprof function

Syntax

Parameters

The summaryRprof function

Syntax

Parameter

Return value

Code example

Code explanation

The `Rprof` function

The `summaryRprof` function