1. Excel Part II More on Plotting Section 8 Fall 2013 EGR 105 Foundations of Engineering I

2. Excel Part II Topics Data (engineers collect and use) –Viewing –What is in the data? –Plotting Data…some ways to look at data Background on Plot Types Transforming data to Log 10 Using Log 10 Scales Homework Assignment

3. Engineering and Data For Engineers, Data… –is useful –often routinely collected –requires interpretation –is used in a variety of ways –can be complex and difficult to work with

4. Data Can Be Complicated

5. Viewing Data Recorded data can show a variety of important trends and patterns Plotting can provide insight –There are different ways to view the data –It is important how data are presented –Often want to see data details on one plot Useful for developing equations Will cover this topic next time in Excel Part III

6. What is in the Data? When you have a set of data, ask… –What do these data tell me? –Is there a trend…a relationship….? –How do the data describe reality? Not always obvious –Sometimes requires different looks –Plotting of data can be very useful

7. Presentation of x-y Data Independent versus dependent variables y y = f(x) x independent dependent

8. Simple Plotting Generate X and Y data to Plot

9. Common Types of Plots Example: f(x) = y = 3x 2 (plots for equations and/or data) Semi-log : Log (Y) Cartesian Semi-log : Log (X) Log-Log : Log (X)-Log (Y)

10. Excel Part II Topics Data (engineers collect and use) –Viewing –What is in the data? –Plotting Data…some ways to look at data Background on Some Useful Plot Types Transforming data to Log 10 Using Log 10 Scales Homework Assignment

11. Lets Review These Plots How were they created? What is – a linear plot – a semi-log plot – a log-log plot – a logarithmic scale Note that here we use Log 10

12. Linear Scale xy=f(x) 0.00 0.100.01 0.200.03 0.300.10 0.400.23 0.500.41 0.600.68 0.600.68 0.801.48 0.902.04 1.002.72 1.508.18 2.0017.89 2.5032.81 3.0053.86 3.5081.89 4.00117.72 5.00215.92 6.00354.43 6.50440.58 7.00538.90 8.00774.73 9.001067.07 10.001420.94 Note: Cannot see details of these points

13. Take Log 10 of x-data xLog (x)y=f(x) 0.00---0.00 0.100.01 0.20-0.700.03 0.30-0.520.10 0.40-0.400.23 0.50-0.300.41 0.60-0.220.68 0.60-0.220.68 0.80-0.101.48 0.90-0.052.04 1.000.002.72 1.500.188.18 2.000.3017.89 2.500.4032.81 3.000.4853.86 3.500.5481.89 4.000.60117.72 5.000.70215.92 6.000.78354.43 6.500.81440.58 7.000.85538.90 8.000.90774.73 9.000.951067.07 10.001.001420.94 Note: Cannot see details of these points Observe: Log (0) undefined Semi-Log Plot

14. Take Log 10 of y-data xf(x)Log (f(x)) 0.00 --- 0.100.01-2.2839873 0.200.03-1.4657030 0.300.10-0.9870373 0.400.23-0.6474186 0.500.41-0.3839899 0.600.68-0.1687529 0.600.68-0.1687529 0.801.480.1708658 0.902.040.3099127 1.002.720.4342945 1.508.180.9129602 2.0017.891.2525788 2.5032.811.5160076 3.0053.861.7312445 3.5081.891.9132248 4.00117.722.0708632 5.00215.922.3342919 6.00354.432.5495289 6.50440.582.6440221 7.00538.902.7315091 8.00774.732.8891476 9.001067.073.0281946 10.001420.943.1525763 Observe: Log (0) undefined Semi-Log Plot

15. Take Log 10 of x-data and y-data xLog (x)y=f(x)log (f(x)) 0.00---0.00--- 0.100.01-2.2839873 0.20-0.700.03-1.4657030 0.30-0.520.10-0.9870373 0.40-0.400.23-0.6474186 0.50-0.300.41-0.3839899 0.60-0.220.68-0.1687529 0.60-0.220.68-0.1687529 0.80-0.101.480.1708658 0.90-0.052.040.3099127 1.000.002.720.4342945 1.500.188.180.9129602 2.000.3017.891.2525788 2.500.4032.811.5160076 3.000.4853.861.7312445 3.500.5481.891.9132248 4.000.60117.722.0708632 5.000.70215.922.3342919 6.000.78354.432.5495289 6.500.81440.582.6440221 7.000.85538.902.7315091 8.000.90774.732.8891476 9.000.951067.073.0281946 10.001.001420.943.1525763 Note: Now can see details of these points Observe: Log (0) undefined Log-Log Plot

16. Excel Part II Topics Data (engineers collect and use) –Viewing –What is in the data? –Plotting Data…some ways to look at data Background on Plot Types Transforming data to Log 10 Using Log 10 Scales Homework Assignment

17. Easier Way Create plots using Log 10 scales – No need to convert any of the data – By hand on paper (available in stores) Semi- Log 10 paper Log 10 -Log 10 paper – Software packages Excel MatLab (in EGR 106 next semester) other

18. Plot Using Log 10 Scale for x xy=f(x) 0.00 0.100.01 0.200.03 0.300.10 0.400.23 0.500.41 0.600.68 0.600.68 0.801.48 0.902.04 1.002.72 1.508.18 2.0017.89 2.5032.81 3.0053.86 3.5081.89 4.00117.72 5.00215.92 6.00354.43 6.50440.58 7.00538.90 8.00774.73 9.001067.07 10.001420.94 Semi-Log Plot Observe: No zero on Log scale - Log (0) undefined Note: Scale variation is logarithmic

19. Plot Using Log 10 Scale for y xy=f(x) 0.00 0.100.01 0.200.03 0.300.10 0.400.23 0.500.41 0.600.68 0.600.68 0.801.48 0.902.04 1.002.72 1.508.18 2.0017.89 2.5032.81 3.0053.86 3.5081.89 4.00117.72 5.00215.92 6.00354.43 6.50440.58 7.00538.90 8.00774.73 9.001067.07 10.001420.94 Semi-Log Plot Observe: No zero on Log scale - Log (0) undefined Note: Scale variation is logarithmic

20. Plot Using Log 10 Scale for x and y xy=f(x) 0.00 0.100.01 0.200.03 0.300.10 0.400.23 0.500.41 0.600.68 0.600.68 0.801.48 0.902.04 1.002.72 1.508.18 2.0017.89 2.5032.81 3.0053.86 3.5081.89 4.00117.72 5.00215.92 6.00354.43 6.50440.58 7.00538.90 8.00774.73 9.001067.07 10.001420.94 Log-Log Plot Observe: No zero on Log scale - Log (0) undefined Note: Scale variation is logarithmic

21. Excel Part II Topics Data (engineers collect and use) –Viewing –What is in the data? –Plotting Data…some ways to look at data Background on Plot Types Transforming data to Log 10 Using Log 10 Scales Homework Assignment

22. Homework Assignment #4 See HW4 on course web site –Import historical data for computer memory prices into spreadsheet –Determine cost in $s/megabyte for each year –Plot data two different ways Linear scale Semi-log scale Discussion of details found in results

23. Homework Assignment #4 Submission Procedures Submit your Excel Spreadsheet with: -all imported and calculated data -each of the two plots -discussion embedded in a text box Send as an email attachment to Prof. Sadd with the subject line egr105_4 (no spaces). Due Date: October 24.