Graphing in Excel

Discussion in 'Mac Apps and Mac App Store' started by pepeleuepe, Feb 23, 2004.

1. pepeleuepe macrumors 6502

Joined:
Oct 27, 2002
Location:
Los Angeles, California
#1
I'm doing lab write ups for my engineering classes and they normally include a couple of graphs. I've been using Excel to do these graphs, but I'm having trouble finding how to control some aspects of the graph. I have a set of data that looks like this:

0.28 V 0.892 mA
0.77 V 0.730 mA
0.99 V 0.658 mA
1.10 V 0.623 mA
2.14 V 0.278 mA
2.30 V 0.222 mA

I want to make a voltage vs. current graph, but when I try to do this on Excel, there's no way to change the x-values. Basically, I get a graph with points (1, 0.28) (2, 0.77) (3, 0.99) for one line and (1, 0.892) .... for the other. Is it possible to make this graph correctly in Excel so I have one line depending on the values above or do I need a seperate program to do that? If so, any suggestions on programs that would work?

I'm pretty sure this should be simple to do in Excel and I'm just missing something, so any help would be appreciated.

Thanks

2. MisterMe macrumors G4

Joined:
Jul 17, 2002
Location:
USA
#2
Re: Graphing in Excel

Excel is a spreadsheet, but a poor graphing or charting application. Back in the day, DeltaGraph was promoted as the charting companion to Excel. For the kinds of graphs you want to make, I find that nothing works better than KaleidaGraph.

3. whocares macrumors 65816

Joined:
Oct 9, 2002
Location:
:noitаɔo˩
#3
You need to select the cross-plot type chart (not histogram or whatever).

Let me take a look for you...

4. whocares macrumors 65816

Joined:
Oct 9, 2002
Location:
:noitаɔo˩
#4
Is this what you mean?
If so, I can send you the file...

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5. pepeleuepe thread starter macrumors 6502

Joined:
Oct 27, 2002
Location:
Los Angeles, California
#5
Exactly. I doubt this is possible, but can Excel make a linear line of best fit as well?

If you could send it to me that would be great davidhun AT usc DOT edu

6. whocares macrumors 65816

Joined:
Oct 9, 2002
Location:
:noitаɔo˩
#6
It's on its way. You can paypal me the \$10 charge

7. pepeleuepe thread starter macrumors 6502

Joined:
Oct 27, 2002
Location:
Los Angeles, California
#7
Alright, I figured it out. You're right, pretty simple, thanks for guiding me through my moment of stupidity (hopefully just a moment)

Thanks again, and the checks in the mail

8. Makosuke macrumors 603

Joined:
Aug 15, 2001
Location:
The Cool Part of CA, USA
#8
If I understand what you want to do, adding a linear fit line ("trendline") is easy;

First select your data set of x-y points. Then select Insert-->Chart and make an XY Scatter type graph (you can do it with or without connecting lines, and you can also have it smooth the connecting line if you want, though that's scientifically poor form).

Then, once you've got your graph, right-click (or command-click) on the data line in the graph; one of the options is "Add Trendline..." This will let you add a best-fit line, logarithmic fit line, etc to the graph.

It's not nearly as powerful for scientific analysis purposes as Kaleidagraph (great application, finally OSX-native), but it'll get the job done if you don't have access to that program.

9. whocares macrumors 65816

Joined:
Oct 9, 2002
Location:
:noitаɔo˩
#9
Yeah, Excel is real bad when it comes to math, statistics and graphing. But it's easy to use and if you understand what it's doing (or should I say *not* doing), then I guess it's ok for simple stuff.