Week Four in Review

Day 1. I was able to work on my graphs for the local clusters. I was able to put on error bars and a legend. We then worked on fitting the information to sample data. We discussed some information that we should look up for the meeting that we have to attend next week. I learned that H-alpha line is created by hydrogen. It emits a wavelength of 656.28nm. This is given off when the hydrogen goes from the 3rd energy level to the 2nd energy level. We worked more with the Schechter function. I then tried to fit it to my local cluster graphs. My graphs were not in log form so it was not working. End Day 1.

Day 2. We went back to fitting the Schecter function to the sample data. We are putting in values in for alpha log l sun and log phi sun. I am attempting to work with a least squared function but am having difficulties because the log l sun is not standing alone as a variable and I cannot get it out easily. Alissa tried to explain chisquared fitting again to me. It is slowly beginning to make sense. End Day 2

Day 3. Rose explains chisquared fitting to us and helps us understand how we would go about coding something using chisquared. Turns out what I was attempting to do was very close to what has to be done. We also get tasks that can be done for the remainder of the week. After some trials we are able to get our bins to the proper sizing. The values however do not agree, but there is a relationship between the values that give us infinity and the values that give us is all the same. I try to write a loop to get that out but cannot find out where the error is coming from. End Day 3

Day 4. I found my syntax error that I was having yesterday. John then explains to us chisquared and finds that we were putting the wrong values in for some of our variables. After lunch we were able to debug and got a best fitting Schecter Luminosity function. I then put the code to the other data blocks Rose gave us. The one set ran but did not fit perfectly. The second file could not be found. End Day 4

Day 5. I realized that my bins were sized oddly and thus the data that I was trying to fit at the end of the day was not working great. Once that was done Alissa and I cross referenced our values for loglsun logphisun and alpha and found that even though our code was different we were now getting the same values. I spent the rest of the day looking up Monte Carlo Simulation, bootstrap resampling and maximum likelihood. Dr. Bellis came in to explain a way to do chisquared fitting. He showed us that there is another way to write that code. I also learned that getting a graph from the brute force way like we did is a way to get the variables by retesting points.