Uploaded by bozemanbiology on 25.11.2012

Transcript:

n this video I'm going to show you how easy it is to graph data using a spreadsheet.

I'm going to be using Microsoft Excel, but you could do the same thing in Open Office,

Numbers for Mac. You could even use Google spreadsheet if you want to do that. And so

let's say I do an experiment where I vary the amount of fertilizer that I give a number

of plants. And then I measure how much they grow. And this is the data that I get. So

you can see that I'm varying it from 2 grams of fertilizer all the way up to 12 grams and

then I'm getting varied amounts of growth. And so if you want to you could copy the Excel

spreadsheet, I'll put a link to it down below the video and you could try doing this on

your own or you could watch me and try one of your own. And so I'm going to switch right

now to Microsoft Excel and you can see that I have the data right here. So I've got the

fertilizer in this first column and then I've got plant growth in the second column. I don't

need to sort these columns, however I could do that if I wanted to in Excel. Basically

what I do is I want to select the data that I want to include in my chart or my graph

and then I'm going to go to insert chart and what you'll find is that nothing happens because

I haven't chosen what type of a graph that I want to do. So I'm going to choose a scatter

plot. A scatter plot is great when we're looking at two sets of number and we want to compare

those. And I'm just going to use the marks scatter plot that looks like this. You can

see that this is way easier than trying to do it by hand. It's already going to figure

out the scale and the axis for you. And so it's much quicker for sure to do this in a

spreadsheet. But changing the graph is sometimes a little difficult so I'll walk you around

that in Excel. First of all I only have one data set so I could just select this plant

growth and I could delete that. You can see here that we've got a title. That title is

not very descriptive. And so to do that, I'm going to give it a better title. So I'm going

to select that box and I'm going to say Relation of fertilizer \'85 Okay, so you can see that

my data looks pretty good. There some space up here that I maybe want to get rid of. And

so to do that in here I'm going to chart layout, so it's right next to chart, I'm going to

click on chart layout and then I can change my axis. And so I'm going to go with my vertical

axis down to axis options and so you can see here that I can set my minimum and maximum

numbers. And so my minimum, since my values start at 18 I could start with a minimum of

15 and the maximum of 100. And you can see that it's going to give me more of that graph.

If I were to do that again for my horizontal axis, so let's go to options, you can see

my low value I could set to 2 and my high value remember is just going to be 12. And

so you can see I'm using more of the graph. What am I missing now? Well I don't have labels.

So I don't have labels here on my x-axis and I don't have labels on my y-axis. To do that

I'm going to go to axis title. And so on the horizontal axis I could add a title below.

So now I can put in here my fertilizer. You want to make sure that's measured in grams.

And I can't see that, it's too small. So I could go back to home here and then I can

change the font size so you can see it. And now let's go over on the y-axis. So I'm going

to go back to chart layout. I'm going to go to axis on the vertical and let's make it

rotated title. And we'll make that, and get right in here, and that's going to be plant

growth. Measure that in centimeters and same thing. I can select all off that. We go back

to home here and we can increase the font size so you can see it. There we go. So we've

got a pretty good graph. We've got our major numbers kind of scaled for us on the side.

What am I missing? I'm missing a trend line. So I'm missing that best fit line. And this

is why I love using Excel to do this. It took me awhile to figure this out. Basically you

select the data first and then I'm going to chart and I'm going to add a trend line. And

you can see that it's going to put in a straight line. But it doesn't look like a linear relationship.

It looks like there's a curve, and so I could try a logarithmic or even a polynomial, that

looks pretty darn good. And so it's going to give me a nice bell, a nice best line.

And so that's my graphs. Super easy to do in a spreadsheet. Super fast especially when

you have a large amount of data you can crank it really, really quickly. And so that is

graphing by spreadsheet. If you'd like me to show you how to graph by hand you could

click on this right here or if you'd like to subscribe to my channel, I'd love that

by clicking right here on subscribe. And I hope that was helpful.