Original subtitles

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Hello everyone and welcome to the lecture on vector basics and this lecture were to learn how to construct

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the vector using the combined function the different rules about constructing a vector and how to use

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the names function to assign names to each element in our vector.

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Let's go ahead and jump to our studio to get started.

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All right so here our studio and let's discuss the vector so vector is just a one dimensional array

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that can hold character numeric or logical data elements and we create a vector by using the combined

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function which is just the letter c of some parentheses.

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So let's go ahead and create a couple of factors.

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We'll start by creating a vector of numerics.

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So I'll call this NBC as the variable name of the assignment operator that little arrow and then use

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the combined function which is that C lose some parentheses and then pass an individual elements separated

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by a comma.

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So let's just say one two three four five separated by commas and notice in my environment I have NVC

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and if I call NABC I get back my one dimensional array of those five elements and we can go ahead and

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call class on NVC and all return numeric since every element in that vector is a numeric.

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Let's go ahead and just see a couple more examples.

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Let's say I wanted a vector of characters let's call it C C and we'll just go ahead and pass in USA

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.

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So you will say s a.

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And remember to put in the C here for the combined function in order to actually create that vector

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c v c and then we have USA.

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All right.

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And if I check the class it's going to return character.

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Finally let's get a vector of logicals.

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So those boolean values and we'll just say T capital T capital F stands for true false LGC is true false

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.

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And if I check the class of that it's a logical.

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All right.

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So something to note here is you may be wondering well what if I try to put in different data types

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into a vector.

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What would the class function return.

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So one of the rules about vectors is that you can't mix data types into the elements of that vector

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array R will convert the other elements to force everything to be of the same class.

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We're going to show you an example of how that would work.

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So going to create a variable v and then going to try to combine let's say a logical true with some

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numbers 20 and 40.

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So if I try doing that they'll notice if I call back that vector V that true has been converted to a

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numeric one.

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And that is going to be because everything else in that vector was numeric.

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So if I call class on the.

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Everything has been converted to a numeric.

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Likewise if I put in false that false would have been converted to a 0 number.

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Let's show you another example of mixing data types.

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Let's say I had a character let's say just USA as a string and some numbers 20 31.

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You might be thinking well how can USA be converted into a numeric.

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Well in this case what are we going to do it's going to convert everything else into a character.

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So everything matches the character of USA.

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So if I call in class VI now everything in that vector is a character Scotius something to keep in mind

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.

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You can't mix up these data types elements in a vector.

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Later on we'll learn about other data structures such as a list which will allow us to mix and match

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different data types into an organizational array.

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All right.

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With that being said let's go ahead and talk about vector names.

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So let's imagine we had a vector of temperature data.

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So I go in and clear this make a new vector called temp's and put in some temperature data.

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Let's go ahead and say 72 degrees 71 degrees and some other just numbers and good and fill these in

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as you see fit 75.

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So let's go ahead and make one for each week day so Monday Tuesday Wednesday Thursday Friday Saturday

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Sunday.

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All right.

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So these are in Fahrenheit hopefully Celsius will be quite hot.

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So we are temps.

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And if you notice very cold temps back I have an array of numbers but no names to associate with each

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of those temperatures stand for.

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So I don't know if the Week starts at Sunday or Monday here and I want to add that information and I

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can do that using the names function.

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So I'm going to go ahead and say names pass in the vector that I want to name and then apply or assign

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a vector of names for the temps vector.

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So it's going to started off on Monday so I'll say Tuesday

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Thursday

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will say Friday Saturday Sunday say the sun makes sure that one last ones in single quotes or double

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quotes.

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OK so I've been able to assign names to each of these elements if I cold temps.

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Now notice the output.

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Now each of these temperatures has been assigned a name.

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This is going to be really useful because now later on we learn about indexing vectors.

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I can use these names to grab data out of the vector.

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Something to note is that I don't have to keep rewriting this long vector of weekdays.

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I could just assign this vector to let's say a vector called days may go ahead and do that in the press

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on the up arrow on my keyboard and let's go ahead instead of using names here.

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When I'm going to do is assigned this to a new vector called days.

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So never called days.

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I have this character vector of day information on Monday Tuesday etc. and then I can do this sort of

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operation names temps

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and assign days to it in this format.

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So usually when you're doing names obviously will get the same result here same vector.

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But as I mentioned usually in reading names you're not going to write this whole long vector multiple

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times feasible times.

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Your first assigned to a vector like so and then use that vector in your name assignment later on.

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OK so let's just go over everything we learned just quickly throughout this lecture.

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We learn how to use the combine function which is c and if you can go ahead and check out the history

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here on this panel.

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So we took out the combined function.

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Learn how to use it learn that vectors can only take up one data type otherwise other data types will

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be converted.

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We learn how to use names and learn about the vector assignment.

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OK later on we're going to learn much more about how to use and work with vectors in our.

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Thanks everyone and I'll see you at the next lecture.