Analyzing calorimetry data using pivot tables in Excel 1. Set up the Source Table: Start in format 1. a. Remove the table of weights from the top to a separate page so the top row has the column labels. Delete the empty rows at the top. There should be no blank rows or columns. b. I like to use the freeze panes feature in the View menu to freeze the date-time columns and the column labels rows. To do this, click on the cell for the first time point (C3 in the sample table) and then click Freeze Panes". The benefit is that you can easily keep track of where you are. The caveat is that you need to make sure you start at the top when doing calculations or copying to paste into a graphing program. 2. Insert a column, and label each row with the group that animal is assigned to. Name that column Group at the top (see example) (see Wendy if you don t know how to quickly clone cells by dragging). I ve deleted some columns and colored the new columns yellow in the examples below so you can see them easily. 3. Calculate net feed consumption: a. Label the column to the right of the feed column net g feed. Label the column next to that net kcal feed. Subtract the first feed value from the second (U4-U3 in Example 1 below). Example 1: net feed calculation b. Press Enter. c. In the second cell of the net kcal feed column, multiply the net g feed value times the caloric value of the feed (5.24 kcal/g in Example 2 below) Example 2: net kcal feed calculation 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 1
d. Press Enter and then clone the calculations for that animal by selecting the two adjacent boxes and dragging. Don t continue dragging down into the next animal or you will get a nonsense calculation for the first time point! Copy the cells for the first mouse and paste into the appropriate position for each successive mouse. The first cell for each mouse should be blank. Example 3: cloning the feed calculations 4. Set up the Pivot Table: Click on any cell in the table. Go to Insert menu and click the Pivot Table icon (on far left). Example 4: Insert Pivot Table command Use the default range, which should be the entire table, and the new worksheet option. Click ok. You will be transported to a new worksheet, with a set of boxes on the right, which are used to set up the table. If your table doesn t look like the image below, see note at the end of this document. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 2
Example 5: a pivot table awaiting data 5. On Design tab, go to Report Layout icon and select Show in Compact Form. 6. From the Pivot Table Field List at top right, add in order, by clicking the checkboxes: Group, Animal number, Date, Time, and whichever measurements you want to analyze (in Example 7 below I have selected XT, RER, H(3) and net kcal feed. You will see them appear in the Row labels area. The order in which they appear in the Row Labels or Column Labels areas will affect the layout of the table. You can change the order at any time by using the mouse to drag them up or down. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 3
Click the box in the Field List to insert into the Row Labels area.. Example 6: adding fields to the pivot table 7. Go back to the master field list at the top and drag XT and your other measured values to the Σ Values area (so now you have them in 2 areas of the layout menu). When you have added 2 items, a Σ Values label will magically appear in the Column Labels area. Drag field from master field list To Σ Values area. Example 7: adding fields to columns 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 4
Then click on the triangle to the right of each field in the Σ Values area and select Value Field settings from the drop down menu. Change Net kcal feed from Count to Sum and the others from Count to Average. You will see the proper values appear on the table, where previously there were 1 s 3. then here 2. then here 1.Click the triangle Example 8: displaying data in desired form. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 5
8. To collapse the date and time fields, use the little boxes that have minus signs in them. Click on one and see that row collapse. You can collapse a whole column by right-clicking and selecting collapse entire field. Example 8: Collapsing the time fields 9. Go to the Row labels box and drag Group and Animal number to the Column labels box put them underneath the Σ values line. Example 9: Displaying groups and mice in columns 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 6
10. Under the Design tab, click on Subtotals, then Do Not Show Subtotals. Example 10: cleaning up the table before copying and pasting the data 11. Filter the dates: To filter the dates, go to the Field List a) click on the Date line. A little triangle will appear on the right. b) Click on the triangle and a menu window will appear. c) Uncheck the days you don t want to analyze (typically the first and last day) and the line that says blank, and click OK.. Example 11: filtering out unwanted dates 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 7
A funnel icon will appear to the right of the field, to tell you it is filtered, and you will see the dates change in your Row Labels column of the data table. Your data are now in a form to copy and paste to Prism to graph your timecourses. After pasting into a Prism data table, you will need to delete the blank data rows created by each date label. Note if you want to scroll through your table at this point and the field list is in the way, you can make it come and go in the Options menu. Use the Field list button on the far right of the Options menu bar to make it disappear and reappear. Also, if you click anywhere outside the data, the Field List will go away. In that case you can bring it back by clicking inside the data. Save your master Pivot Table At this point, I usually use this page as a master table, and make copies to analyze specific time intervals or subsets of animals. This allows you to keep a record of each specific analysis without repeating the whole setup process. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 8
Filtering to analyze specific time periods 12. There is sometimes a lot of traffic in and out of the room in the early morning, so it s best to confine the daylight period to times after 10 am. To look at only the times between 10 am and 7 pm a) click on the Time triangle and select Date filter, then select the between option b) enter 10:00 and 19:00 (or use whatever other startand end- points you want). Click OK. c) You will see the restricted range of time points on your table: Note: If you want to look only at the dark period, use the is not between option. Bear in mind that the time with which each datapoint is labeled represents values measured during the preceding 30 minutes. Example 12: restricting data to the resting period 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 9
13. At this point you may collapse the date fields so that you are viewing the average values for that period (right-click on the minus sign in front of the date, and select Collapse Entire Field : Caution: label your worksheet tab so you are reminded that these are mean values for a restricted period, not 24- hour values! The funnel next to Time in the Pivot Table Field List is also a reminder. Example 13: data collapsed to average for period and dates Filtering to analyze points of minimum activity 14. To look at resting metabolism, a) Go to H(3) in the field list, click the triangle, select Value filters, and the less than option. b) In the drop-down at the left side of that window, (i) change the H(3) to Average of XT. (ii) Set the middle window to is less than (iii) Enter the maximum value of XT for which you want to know the H(n) value (I ve been using 150); Click OK. Example 14: filtering activity Now your H values display only those that correspond to a total activity of less than 150 counts for that period. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 10
Depending on how active your animals are during the day, you might want to play around with the maximum XT value to use in the step above. To monitor how many data points you have at any given XT, drag XT from the pivot table field list to the Σ Values list and leave it as count of XT. Now at the bottom of the count of XT columns you will see the number of data points you have for each animal. The finished product - at this point your table should look like the illustration below: 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 11
Graphing time courses and mean values: If you have the same number of animals in each group, you can easily copy and paste an entire line of data into Prism. Caution!!! If you copy and paste a subset of the data into Prism, the software may move your Y values out of register with the X column to put something in the top row of data.. Rearranging the table: To rearrange the data so that each parameter is displayed in a single column: drag Group and Animal No. from the Column Labels box to the Row Labels box: Graphing covariance: 1. Copy your columns of data into a new source table, and add columns for mouse no., group, and lean mass (or whatever other value you want to use on the X-axis). 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 12
2. Click a cell inside this table and set up a new pivot table. a. Lean mass (or whatever parameter you will use on the X-axis) goes in the Row Labels area. b. Group and Mouse No. go in the Column Labels area, beneath Σ values. c. The values to plot on the Y-axis go in the Σ values area. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 13
3. In Graphpad Prism, set up an XY table and graph, points only, plot each replicate. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 14
Copy and paste your data from the spreadsheet. CAUTION!! If you copy only part of a table, Prism will shift lines up or down to make something appear in the top line. Double check that your Y values are correctly aligned with your X values!!! kcal expended/hr 0.65 0.60 0.55 0.50 0.45 Resting energy expenditure A rh3 B rh3 0.40 15 20 25 30 35 Final Lean Mass (g) Under the Analyze menu, select linear regression and the groups you want to analyze (if different than the default selection provided by the software). 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 15
When you click OK a second menu will appear. Click Test whether slopes and intercepts are significantly different. This will draw regression lines on your graph. You can view the analysis by clicking the link that is highlighted in the left-hand column: 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 16
Notes: a. If you change column names or add a column inside the original (format 1) source table, you can update the pivot table by going to the Options tab and clicking Refresh. You are likely to get a security warning click OK to enable the updating. b. If you add a column at the edge of the table, you have to expand the range of the table before you can refresh: go to the Options tab, choose Change Data Source and edit the range to include the new column. The dynamic dotted line shows you the data included in the pivot table. Then click Refresh. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 17
c. Sometimes you might see a funky template (see example below) instead of the one shown in Example 1. It defaults to this format if your spreadsheet was saved as an xls instead of xlsx file. If your table doesn t look like the first example, but instead has a bunch of boxes that say to drop things there, then go to the Options menu, and select Options. Select the Display tab and uncheck the box for Classic pivot table and click OK. 7/13/2012 W:\Core B, Metabolism Chambers\calorimetry docs\calo data handling instructions Page 18