Graphs for lab reports. HOW?

[Dimitris]

Well is there anyone to tell me how graphs are getting done in excel 2007? Is there any guide for making graphs for the experiments? Because my Physics teacher told me that it is magnificent to do graphs electronically with uncertainties, error bars and etc...

I NEED HELP :surrender:

[Procrastination]

I guess this is your first lab? God, I'm a May 2013 candidate too and I've already made 9. So basically here's what you have to do:

1. Build up a table in excel with four columns, that's right. Four. In the first one you're going to introduce the recorded values for your independent variable and in the second one, the measurements for the dependent one. Excel takes this order to make the graph. Say, your independent variable is time and the dependent one is distance. Time (With its corresponding uncertainty) goes in column A and Distance (with its corresponding uncertainty) in column B. Uncertainties might be calculated.
   
2. In the third and four columns you're going to plug in your calculated uncertainties, they might be constant or different. Hence, in the third one you write down the uncertainty for time so let's take that it is 0.2s due to the instrument used. You write down in every space of the column 0.2. In the other hand, in the fourth column you write down the uncertainties for distance (your dependent variable). Let's suppose they are 4m, 2m, 2m, 4m, 3m, 5m, 2m, etc... You have to write these values in each corresponding line of column D. These values are usually calculated.
   
3. Click insert. Dispersion, select the first option.
   
4. A white window appears. To plug in the values you should click on "select values" or "select data"
   
5. Click "add"
   
6. In the first appearing space you write down the title of your graph. Now, you should select the values for "x" and "y" so just click on the red arrow and select them by dragging the mouse.
   
7. After you're done, click accept.
   
8. You should have now a graph with all of your data plugged in but without error bars. In order to make them click the graph, click presentation, click analysis, click error bars and then, click on more options. (I'm translating from my Excel which has as spanish as the predetermined language, the names of the things you have to click might not be the same).
   
9. Now, you should pay attention if youre doing your horizontal or vertical error bars. This is stated in the title of the emerging window. It can be both. Click personalized. Now click on "specify data" or "specify values". A window pops out saying "personalized error bar". Here you'll have to select the uncertainties you've written before for the positive and negative values, which is actually the same. Click on the red arrow for the positive error bars, now youll drag the mouse on the uncertainties you've written before, attention! If you're plugging in the vertical error bars you must select the data on column D. If you're plugging in the horizontal ones, drag your mouse on the values in column C.
   
10. For the negative values you do the same thing. Click accept and then close.
    
11. To draw the error bars for the other axis you must do the following: right click in one of the horizontal or vertical error bars (the ones you've not personalized yet) which just pop out thanks to excel. Click on "format of error bar". You must carry on the same process I've stated before.
    
12. Voila! You have a graph with personalized error bars now. To draw the line of best fit and to calculate the gradient you must do the following: Right click on one of the values of the graph. Click on add best fit line. A window appears, select lineal if you consider this is the behaviour of your recorded measurements. (Most common option). Click on present graph's ecuation.
    
13. You're done. However, you have to calculate the uncertainty of your gradient by drawing the maximum and minimum gradients. You should create two additional tables and build them up, if you don't know how to do this ask your teacher, they're not that difficult. After you have them with their corresponding best fit lines just carry on the following formula: (Max.gradient-Min.gradient)/2. That's the uncertainty of your first gradient which usually means something depending on your lab report.
    

Phew Hope it helped.

Procrastination

[Dimitris]

I guess this is your first lab? God, I'm a May 2013 candidate too and I've already made 9. So basically here's what you have to do:

1. Build up a table in excel with four columns, that's right. Four. In the first one you're going to introduce the recorded values for your independent variable and in the second one, the measurements for the dependent one. Excel takes this order to make the graph. Say, your independent variable is time and the dependent one is distance. Time (With its corresponding uncertainty) goes in column A and Distance (with its corresponding uncertainty) in column B. Uncertainties might be calculated.
   
2. In the third and four columns you're going to plug in your calculated uncertainties, they might be constant or different. Hence, in the third one you write down the uncertainty for time so let's take that it is 0.2s due to the instrument used. You write down in every space of the column 0.2. In the other hand, in the fourth column you write down the uncertainties for distance (your dependent variable). Let's suppose they are 4m, 2m, 2m, 4m, 3m, 5m, 2m, etc... You have to write these values in each corresponding line of column D. These values are usually calculated.
   
3. Click insert. Dispersion, select the first option.
   
4. A white window appears. To plug in the values you should click on "select values" or "select data"
   
5. Click "add"
   
6. In the first appearing space you write down the title of your graph. Now, you should select the values for "x" and "y" so just click on the red arrow and select them by dragging the mouse.
   
7. After you're done, click accept.
   
8. You should have now a graph with all of your data plugged in but without error bars. In order to make them click the graph, click presentation, click analysis, click error bars and then, click on more options. (I'm translating from my Excel which has as spanish as the predetermined language, the names of the things you have to click might not be the same).
   
9. Now, you should pay attention if youre doing your horizontal or vertical error bars. This is stated in the title of the emerging window. It can be both. Click personalized. Now click on "specify data" or "specify values". A window pops out saying "personalized error bar". Here you'll have to select the uncertainties you've written before for the positive and negative values, which is actually the same. Click on the red arrow for the positive error bars, now youll drag the mouse on the uncertainties you've written before, attention! If you're plugging in the vertical error bars you must select the data on column D. If you're plugging in the horizontal ones, drag your mouse on the values in column C.
   
10. For the negative values you do the same thing. Click accept and then close.
    
11. To draw the error bars for the other axis you must do the following: right click in one of the horizontal or vertical error bars (the ones you've not personalized yet) which just pop out thanks to excel. Click on "format of error bar". You must carry on the same process I've stated before.
    
12. Voila! You have a graph with personalized error bars now. To draw the line of best fit and to calculate the gradient you must do the following: Right click on one of the values of the graph. Click on add best fit line. A window appears, select lineal if you consider this is the behaviour of your recorded measurements. (Most common option). Click on present graph's ecuation.
    
13. You're done. However, you have to calculate the uncertainty of your gradient by drawing the maximum and minimum gradients. You should create two additional tables and build them up, if you don't know how to do this ask your teacher, they're not that difficult. After you have them with their corresponding best fit lines just carry on the following formula: (Max.gradient-Min.gradient)/2. That's the uncertainty of your first gradient which usually means something depending on your lab report.
    

Phew Hope it helped.

Procrastination

I really thank you!!!! the how-to of yours was really usefull and helpfull!!! thank u very much!!! actually no it is my 10th, but i didn't really know how to do graphs and i was just experimenting and i want to perfect it, thats why. Thank you very much for your time!!!! it definitely helped!!!!

[Procrastination]

You're welcome Oh, I thought it was your first one since I my first one already included all of these things, crappy generalizations. anyways, if you have another question don't be afraid of contacting me.