R will not recognize imported datasets in markdown

Question

When tested with 'mtcars', markdown will have no problem knitting the code in html, however when I use the name of an imported data set:

```{r,echo = FALSE}
names(mtcars)
```

I get the following error:

Error in eval(expr, envir, enclos) : object 'Fitbit' not found
Calls: <Anonymous> ... handle -> withCallingHandlers -> withVisible -> eval -> eval

Can anyone help me with why? I get an error every time I try to plot a chunk even though the test run went smoothly as well. If I use a chunk, I get an error with {r} or {r, echo = FALSE}.

Ex:

---
title: "Homework"
author: "name"
output: html_document
---


```{r,echo = FALSE}
names(Fitbit)
```

Output Error:

Quitting from lines 9-10 (Example-Homework-Problem.Rmd) 
Error in eval(expr, envir, enclos) : object 'fitbit' not found
Calls: <Anonymous> ... handle -> withCallingHandlers -> withVisible -> eval -> eval
Execution halted

Answer 1

I am posting this as an answer for your convenience, I will delete it as soon as you try this out:

```{r}
setwd("C:/Users/nataliakhodayari/Desktop")
fitbit <- read.csv("Fitbit.csv")
names(fitbit)
hist(fitbit$Miles,xlab = "Miles",main = "Overall Miles Traveled")
```

If the directory cannot be changed, try this:

```{r}
fitbit <- read.csv("Fitbit.csv")
names(fitbit)
hist(fitbit$Miles,xlab = "Miles",main = "Overall Miles Traveled")
```