# Lkelly9 Week 2

• Individual Journal Entry
• Shared Journal Page

## Electronic Lab Notebook

### Purpose

The scientific purpose of my investigations was to plot two vectors, u and v, on a graph and to model the logistical growth for four different rates on one plot.

### Workflow/Methods

#### Part I: Create a script that includes the following elements

• Define a vector u containing the elements 1,2,3,4,5,6,7,8,9,10 using the colon operation
• u = [1:10]
• Define another vector v containing elements that are the square of the vector
• v = u.^2
• Plot v versus u (make sure you know what that sentence means!!) using circles on the points that are connected with dashed lines
• plot(u,v)
• Add title: title('V vs. U')
• X-axis label: xlabel('u')
• Y-axis label: ylabel('v')
• Save your plot as a TIFF file
• Save your data into an excel spreadsheet using the MATLAB command xlswrite
• Declare the file name: filename='insertfilenamehere'
• Put u and v together in a vector: A=[u;v]
• Save into an excel sheet: xlswrite('insertfilenamehere',A)

#### Part II: Create a script to compare logistic growth curves

• Define a vector t starting at 0, ending at 1, in steps of 0.01.
• t = [0:0.01:1]
• Define K = 10 and x0 = 2 for carrying capacity and initial population size.
• Plot logistic growth curves for growth rates 0.5,1.0,1.5, and 2.0.
• For r=0.5: y1=(x0*K)./(K*exp(-0.5*t)-x0*exp(-0.5*t)+x0)
• For r=1.0: y2=(x0*K)./(K*exp(-1.0*t)-x0*exp(-1.0*t)+x0)
• For r=1.5: y3=(x0*K)./(K*exp(-1.5*t)-x0*exp(-1.5*t)+x0)
• For r=2.0: y4=(x0*K)./(K*exp(-2.0*t)-x0*exp(-2.0*t)+x0)
• Plot these four curves together in one figure, and add appropriate labels, title, and legend.
• plot(t,y1,'m',t,y2,'r',t,y3,'b',t,y4,'k')
• Save your plot as a TIFF file

### Conclusion

My main finding for today's project was that MATLAB can be manipulated in a variety of ways to model data. Furthermore, the logistic growth curves, assuming I executed them correctly, were fairly linear and they did not level off at any point. I accomplished my purpose of plotting vectors u and v and plotting four different logistic growth curves in the same figure.

### Acknowledgements

• I worked with my homework partner Cameron M. Rehmani Seraji face-to-face in the computer lab outside of class. We worked on the MATLAB portion of the assignment together.
• I worked with Ben G. Fitzpatrick through email one time. He helped me with the logistic growth curve.
• Except for what is noted above, this individual journal entry was completed by me and not copied from another source
• Lauren M. Kelly 01:22, 26 January 2017 (EST)