Reading .csv files into RStudio

Hi. In this video I'm going

to show you how you can read in dot.

TXT files into R

so you can use that data to perform data
analysis on.

So first thing you always need to do

is something we talked about in a previous
video is set in your working directory.

So make sure that you have navigated
to the folder

of where your data set
is that you want to bring into R.

I have done so already.

I want to bring in this mri dot.

TXT file.

Okay.

The next thing you need to do
is to read in a dot.

TXT file is to use the function read

dot table and inside the parentheses.

The first thing you'll put in there

is the name of the file
that you want to bring in.

Now R is case sensitive,
so you need to have it

be exactly how it's shown here.

Spaces underscores everything.

Plus you need to include the file
extension okay.

And the next, important thing

that you need to also, specify

is whether or not,

you have a header to kind of help
illustrate this.

Let's go ahead and read this data into R

okay.

What it will do is it'll show up down here

and it says, hey, I saw this data set
and this is what it looks like.

So here it is.

Notice that it looks like my data has
this first call.

Has this first at the top
here has different column titles or like

headers, you know, to explain
what each of these variables are.

But when I read it into R, notice
that it counted

this first line as a piece of data
as an observation.

When these are really actually
just the column titles or the header.

So what we need to do
is we need to specify

with a comma inside the parentheses

that are a header is equal to true,

meaning that we are telling R that,

hey, we have a header for our data
like we have column titles.

So do not treat that very first row
as a piece of data.

Treat it as the column titles.

Notice how are internally just called

all these v1 v2 like column one,
column two, column three.

Watch what happens
if I change this to header equals true.

Now you can see that R realized

or was told that this very first line

is the header or the column titles.

So now we can see that
it is actually counting the right things

as observations of data
and not counting these headers

as, as data.

If you do happen
to not have headers on your data,

and you want R to do it for you,

you can always specify header equals false
saying, hey, I don't have column titles.

Can you just call them v1, v2 for me.

But most of the time
you will have column titles.

So don't forget to do this.

Header equals true.

Also notice that I'm doing it in all caps.

If I type it out

like this, R doesn't realize
and it doesn't change color,

doesn't know that it's
meaning the true value.

It's just thinking
you're typing the word true.

So you need to make sure it's in all caps.

Or you can just say capital T
or capital F.

But good practice

is to type out the full word.

Now you may have this data,
but if you want to be able to do

any kind of, analysis
with it, it's very important to,

make sure you, save it

and use what we call the assignment

operator to save it into your environment.

So that way you can use it later. Okay.

So instead of just running this
read table,

command put in front of it the name of
whatever you want to call your data.

So let's say
I want to call this data MRI data.

And then

what you will put here is what we call
the assignment operator in R,

it is a, less than sign with a dash.

And it's kind of like a little arrow.

So what that's doing is it's saying,
okay, this part right here,

when we ran that notice,
it just said boom, here's the data.

So what this
now this whole line of code will do is it

will now take this data
that we brought into R

and it will then store it into something
like a little box

called MRI data.

So that way you can use it later.

Notice when I run this piece of code

what happens over here
in your global environment.

It now saves your data as MRI data.

And it notices that there is 15
observations of 11 variables,

which is true.

We have 15 observations
and 11 different variables.

It does not show the data set here.

But you do see that has now been saved.

So now anytime
you want to do anything with your data,

all you have to refer
to it as you say, MRI data.

And when you

run it or do anything with it, it'll know
that you're talking about this data set.

All right.

That is how you can read in

txt files into R
and the importance of saving it.

And in your global environment.

And also don't forget to set your working
directory at the very beginning.