Holy Hell
This is Disturbed’s cover of Simon and Garfunkel’s Sound of Silence. It is amazing.
This gave me chills, seriously. He’s got a beautiful voice.
Wow, I’m bad at blogging
So, uh…hi.
It’s been awhile, huh? What, like five months?
(Sorry.)
Lots of things have happened in these past few months, and thing have gotten hectic and weird and when it comes to blogging in general I’m basically like this anyway:
So you can imagine what happens when I get busy.
Anyway, if you want the TL;DR version of the past five months, here are the highlights:
- I finished last semester without totally screwing up STAT 721
- Nate and I got engaged!
- I surpassed my goal of 2,500 walking miles for last year
- I’m stopping school after I get my Master’s this summer. It’s a long story.
- I forgot to update my blogs. BUT YOU ALREADY KNEW THAT
Yeah. Other stuff happened too, but those are the big things.
Oh, and of course:
I’ll try to be better, I promise!
I AM CAPTAIN SPONGE
When was the last time you got a nose bleed?
I get them every month or so, sometimes twice a month. It might be because it’s fairly dry up here.
Do you keep magazines by your toilet?
Nope.
If you were a waiter/waitress, would you make good tips?
Ha. Probably not.
Have you ever stolen a road sign or traffic barrier?
Nope.
What are the best kind of Girl Scout cookies?
Trefoils. Anyone who tells you otherwise is a liar and an awful person in general.
When was the last time you purchased alcohol?
Never?
Do you find it attractive when a guy actually shows his feelings?
Of course. Everyone should be able to express their feelings.
Are you a fussy eater?
I am. Deal with it.
List everything you ate and drank today:
An English muffin and some water.
How are you sitting?
LIKE A BOSS
Waiting for something?
I’m waiting for the semester to end. I’m waiting to see what will happen in my future. I’m waiting to get a break from all this. I’m basically a ball of anger and anxiety right now.
Do you like pretzels?
Not really, no.
Do you wait until you’ve completely finished a certain makeup product before you buy a new one?
Yup. I haven’t bought new eyeshadow in like 13 years. Which is probably bad, but hey.
Did you wake up before 8:00 a.m. this morning?
HA.
Have you ever told anyone you were okay when you really weren’t?
Welcome to the past two months, yo.
Do you have reason to cry right now?
It’s me. I can always cry over something.
How many sodas a week do you have?
Zero!
Do you shop at Victoria’s Secret?
I like La Senza better.
Are you into sports?
Is walking a sport? I like to watch baseball, I suppose.
Can you easily touch your toes?
I have never been able to touch my toes. I always failed the “flexibility” part of that Presidential Fitness Test. I could do like 13 pull-ups, but could never touch my toes.
What did the last shoes you wore look like?
They’re my walking shoes!
What do you currently hear?
My compy making noises, Jazzy squeaking.
Have you ever done yoga?
BAH.
Do you text a lot?
I text my mom all the time.
Do you have a fax machine at home?
Nope.
Do you know anyone who has diabetes?
My grandma. My cousin.
Have you ever had to block anyone online?
No. I just ignore people and hope they go away.
Are you afraid of thunder and lightning?
I love thunder and lightning. Unless I’m out walking in it.
Are you a shop-a-holic?
Nah. I like to look at things, but I rarely buy a lot.
Are you healthy?
Healthier than most, I think.
Homesick
You wouldn’t think I’d miss this little dink of a town, but right now, I miss it very much.
I’m excited to go back for a week or so in May to hang out with my mom/see Annabelle/walk around on my old routes. The cheaper groceries/clothes/everything will be a nice change for a bit, too.
Have more pics.
GUESS WHO’S IN A BAD MOOD?
(It’s me.)
I’m so ready for this semester to be over. I’m so ready for school in general to be over.
Just…ugh.
(Sorry. I’m really just not in a blogging mood today.)
I WON A THING
I got another TA award! Yay! I got one for fall 2014; this one is for fall 2015 (they just announced it, though, haha).
I think the reason I didn’t get one in Winter 2015 was because I had only like 8 people in my lab the day I ended up handing out the little review forms, and I don’t think it was a big enough sample for them to even count it (their reasoning is that if there are too few people filling it out, those people can be more easily identified, and the survey is supposed to be anonymous).
Anyway. Woo!
Week 12: The t Test for Two Independent Samples
Today we’re going to talk about our first test involving two samples: the t test for two independent samples!
When Would You Use It?
The t test for two independent samples is a parametric test used to determine if two independent samples represent two populations with different mean values.
What Type of Data?
The t test for two independent samples requires interval or ratio data.
Test Assumptions
- Each sample is a simple random sample from the populations they represent.
- The distributions underlying each of the populations are normal.
- The variances of the underlying populations are equal (homogeneity of variance; a formal test for this will come in a later week).
Test Process
Step 1: Formulate the null and alternative hypotheses. The null hypothesis claims that the two sample means are equal. The alternative hypothesis claims otherwise (one population mean is greater than the other, less than the other, or that the means are simply not equal).
Step 2: Compute the t-score. The t-score is computed as follows:
Step 3: Obtain the p-value associated with the calculated t-score. The p-value indicates the probability of a difference in the two sample means that is equal to or more extreme than the observed difference between the sample means, under the assumption that the null hypothesis is true.
Step 4: Determine the conclusion. If the p-value is larger than the prespecified α-level, fail to reject the null hypothesis (that is, retain the claim that the population means are equal). If the p-value is smaller than the prespecified α-level, reject the null hypothesis in favor of the alternative.
Example
The data for this example come from the midterm scores of my lab section for STAT 213. While lab attendance is technically optional, the students’ attendance is recorded for each lab (if they show up to lab, they basically get additional instructional materials unlocked to help them study more).
I wanted to see if there was a significant difference in the average midterm score for students who attended lab at least half the time (sample 1) and students who attended lab less than half the time (sample 2). Specifically, I wanted to test the claim that attending lab more frequently was associated with a higher midterm score. Here, n1 = 17 and n2 = 13. Set α = 0.05.
H0: µ1 = µ2 (or µ1 – µ2 = 0)
Ha: µ1 > µ2 (or µ1 – µ2 > 0)
Computations:
Since our p-value is smaller than our alpha-level, we reject H0 and claim that the population means are significantly different (with evidence in favor of the mean being higher for those attending labs more often).
Example in R
x=read.table('clipboard', header=T)
attach(x)
x1=subset(x,attended==1)[,1] #attended lab
x2=subset(x,attended==0)[,1] #did not attend lab
n1=length(x1)
n2=length(x2)
xbar1=mean(x1)
xbar2=mean(x2)
s1=((sum(x1^2)-(((sum(x1))^2)/n1))/(n1-1))
s2=((sum(x2^2)-(((sum(x2))^2)/n2))/(n2-1))
t = (xbar1 - xbar2)/sqrt(((((n1-1)*s1)
+((n2-1)*s2))/(n1+n2-2))*((1/n1)+(1/n2))) #test statistic
pval = (1-pt(t, n-1)) #p-value
I DON’T HAVE A TITLE, WORDPRESS, STOP PRESSURING ME
Heeeeeeeeeeeeeeeeeeeeeey have a drawing. Blah.
Jazzy Cat
‘Sup, fools?
So I haven’t taken any pictures of Jazzy using my actual camera, mainly because at first I thought she’d be afraid of it, and then later just never had it around. The other day, though, she was posing on the coffee table and was half asleep, so I was able to get my camera and get two decent shots of her.
Sorry, just wanted to spam you with a few cat pictures, ‘cause I don’t do that enough on here.
To Survey or Not to Survey?
SPRING FORWARD, BITCHES!
Hi.
Have a survey.
When was the last time you moved to a new house?
June 2015. Hopefully that will be the last move in a looooong time.
What’s the most interesting thing in the room you’re in?
Nate. :)
On a weekend, how long do you typically lay in bed before getting up?
When I was on my own, probably around noon or so. Now it’s a few hours earlier. Usually.
How long was your longest relationship?
My longest relationship is my current one! 15 months and one day.
What’s your star sign?
Aquarius.
Now what’s the star sign of your significant other or crush?
Scorpio!
Which cities and/or states have you lived in?
Moscow (ID), Troy (ID), Vancouver (BC), London (ON), Tucson (AZ), and Calgary (AB).
What can you tell me about how your parents met and how old were they?
All I really know is that they met at the U of I.
Are you in college and if not, where do you want to go to college and why?
Hahahahahaha. I’ve been in college for 10 years now. I’m a freaking professional at this college stuff.
What makes your bedroom special to you, or what’s your favorite part about it?
Nothing, really. It’s a room, it’s got a bed in it, I crash in the bed. The end.
When washing your hands, do you wet your hands or put soap on first?
I wet my hands first. Putting soap on first is weird, yo.
If you had to pick one chore to do today, what would it be?
Dishes. I don’t mind dishes. Though they don’t need to be done right now.
When was the hardest you ever cried and what was the circumstance?
Due to the fact that I’ve probably spent about 30% of my life crying, I am unable to pinpoint an exact circumstance that led me to cry the most.
Where do you usually buy your clothes?
Thrift shops, like Goodwill or whatever that one up here is. Can’t think of the name.
Are your fingernails currently short or long?
Short.
If you had to be a school teacher, which subject would you teach?
Statistics! I don’t care if “school teacher” sounds like it implies kindergarten/elementary school-level teaching. Those 6-year-olds would know how to do hypothesis testing like nobody’s business.
When it comes to relationships, are you the jealous type?
Used to be. I try not to be anymore.
What do you usually order at Jamba Juice?
Never been to a Jamba Juice.
How long have you had your cell phone?
Since summer 2014.
Which gift cards do you have in your wallet?
None.
Which celebrity do you think is the prettiest nowadays?
Leibniz.
Random Questions
Who did you last talk to about the person you love?
My mom. Wedding stuff!
Is there something you’re not looking forward to?
Everything related to school. Every. Thing. My motivation is so far down the toilet it’s actually become reclaimed and is being used to water lawns.
Would you prefer a thunderstorm or for it to be snowing?
Depends. Am I out in it? Snow. Am I watching it from the nice warm inside? Thunderstorm.
What’s your favorite thing to shop for?
Nothing, really. Not huge on shopping.
Who was the last person you talked to last night before bed?
Nate!
Is there anyone you trust that you shouldn’t?
Probably.
Are you excited for anything?
Going back to Moscow for a stint and seeing my mom and Annabelle. I miss both of them.
Has anyone of the opposite sex been on your mind lately?
Yes.
Will you be in a relationship in the next month?
I hope so!
Do you think the last person you kissed cares for you?
I hope so!
Thinking back five months ago, were you single?
NOPE
Do you have a lighter in your room?
No.
What’s to the right of you?
The wall.
Are you in a good mood?
Not as good as I could be.
Are you wearing socks?
Yes. I’m freaking freezing.
What’re you thinking about?
The future. And stressing about it.
What color shirt are you wearing?
Orange.
Do you love anybody?
Damn straight.
Have you kissed a boy in the last three days?
He is no boy. He is a MAN!
Who was the last person you sat next to on a bus?
Some random dude? I don’t pay attention, I just avoid eye contact and hope I’m not stinky.
Will your next hug take place within less than three hours?
No, but that’s just because it’s like 3 AM and Nate and I won’t be awake together until the morning.
What was the last drink you consumed?
Water.
Where are you currently placed?
IN SPACE
Have you ever had your heart broken?
Yeah. Sorta. Who cares.
Do you want kids?
NONONONONONONO.
(No.)
If someone loved you right now, would you want them to tell you?
Sure.
Have you ever fallen completely in love?
Absolutely.
Do you believe in celebrating anniversaries?
I’m more about just acknowledging them than celebrating them.
Have you ever been given eleven roses and a fake rose?
Can’t say that I have.
Who’s with you at the moment?
Jazzy.
Who last walked through your front door?
Me!
Where are your favorite shoes?
On their little pad in the hallway.
What color’s your underwear?
Tan.
Has a tragedy ever happened in your life?
Sure.
Are there some songs you can’t listen to because they remind you of someone?
Nah.
What’s the biggest annoyance in your life right now?
DON’T EVEN GET ME STARTED
When will your next kiss be?
Tomorrow!
Who last called you?
I have no idea. It’s been awhile since I talked to someone over the phone. My dad, maybe?
Have you ever kissed someone with braces?
Nope.
Where is/are your best friend(s)?
DO NOT HAVE
Week 11: The Single-Sample Runs Test
Today we’re going to look at another nonparametric test: the single-sample runs test.
When Would You Use It?
The runs test is a nonparametric test used in a single sample situation to determine if the distribution of a series of binary events, in the population, is random.
What Type of Data?
The single sample runs test requires categorical (nominal) data.
Test Assumptions
None listed.
Test Process|
Step 1: Formulate the null and alternative hypotheses. The null hypothesis claims that the events in the underlying population (represented by the sample series) are distributed randomly. The alternative hypothesis claims that the events in the underlying population are distributed nonrandomly.
Step 2: Compute the number of times each of the two alternatives appears in the sample series (n1 and n2) and the number of runs, r, in the series. A run is a sequence within the series in which one of the alternatives occurs on consecutive trials.
Step 3: Obtain the critical value. Unlike most of the tests we’ve done so far, you don’t get a precise p-value when computing the runs test results. Rather, you calculate your r and then compare it to an upper and lower limit for your specific n1 and n2 values. This is done using a table (such as the one here*). For the values of n1 and n2 in your sample (labeled on this table as n and m), find the intersecting cell of the two values.
Step 4: Determine the conclusion. If your r is greater than or equal to the larger number or smaller than or equal to the smaller number in that cell, you have a statistically significant result, meaning you reject the null (that is, reject the claim that the distribution of the binary events in the population is nonrandom). If your r is between the smaller and larger number, fail to reject the null.
Example
For this example, I decided to see if the coin flips from the website Just Flip a Coin were, in fact, random. I “flipped” the coin a total of 30 times and recorded my results as “H” for heads and “T” for tails. This series is recorded below.
H0: The distribution of heads and tails in the population is random
Ha: The distribution of heads and tails in the population is nonrandom.
THTTHHHHHHTHTTHHTTHHTHHHTHHHHT
Computations:
T H TT HHHHHH T H TT HH TT HH T HHH T HHHH T
n1 = 19 (heads)
n2 = 11 (tails)
r = 15
According to the table, my lower bound is 9 and my upper bound is 21. Since my r is in between these two values, I do not have a statistically significant result. I fail to reject H0 and claim that the distribution of heads and tails in the population is indeed random.
*Note that this table, like many others, only has a maximum of 20 for either n or m, and is constructed with α = 0.05 for the two-sided test and α = 0.025 for the one-sided test.
Example in R
No R example this week, since it’s probably more work to do this in R than it is to do it by hand, haha.
[ignore this]
There’s something I’ve been meaning to blog about for…oh, about four years now. But I’ve never felt removed enough from this thing to be able to actually write about it.
But I feel like it’s almost time to just do it. Just write about it. It’s a big deal, it’s an important thing that’s happened, and it’s something that I haven’t ever really talked about to anyone. I’ve mentioned it in passing to a few people, but have never gone into any detail.
But I think it’s almost time to acknowledge it.
Anyway.
I’m not going to talk about it now, ‘cause I don’t want to just yet, but I just wanted you to know that there might be a pretty serious blog post in the near future.
So yeah.
Tunes for All!
2016 has been a fantastic year for music thus far. I don’t really have anything to blog about today (but do I ever, really?), so have some of my favorites. I’ve posted a few of these on here already, but it’s my blog, so I’m just going to post them again. Take that!
Oh, it’s just a little breezy out here–OH GOD
You know what’s fun? Walking in wind warning-worthy weather.
Oh wait, that actually kind of sucks.
I’m pretty sure I’m more dust than human right now.
But I got 15.87 miles in, which puts me over 550 for the year. Snazzy.
That’s all. My eyes hurt and I’m sure I’ve ingested more than my daily recommended value of dust and debris.
The Cat’s Meow
JESUS CHRIST, MARKIPLIER
Edit: paused it at just the right spot.
TWSB: Blacker than the Blackest Black Times Infinity (Part II)
I did a post quite a while ago on super black material, but it looks like they’ve recently come up with something that’s even blacker.
Surrey NanoSystems, a British company, have improved their Vantablack material so that it absorbs more than 99.96% of the light that hit it—more than their original Vantablack, which had first been created in 2014. In fact, the new material absorbs so much light that scientists are unable to measure exactly how black the material is. You can shine a laser pointer onto it and the laser seems to disappear.
Vantablack is made by packing carbon nanotubes so tightly together that light can get in but can’t escape. Here’s a crumpled up piece of aluminum foil painted with Vantablack.
Freaky, huh?
Walk like an Encryption
So this summer’s going to be super busy. Things to do include:
- Wedding planning
- Future planning
- 2 trips to Moscow
- Working on thesis
- TA-ing
- Getting married!
- Defending thesis/graduating
- Looking for a job (and hopefully getting one)
*stresses out*
*realizes that most of these things are good*
*continues to stress out anyway*
Woo.
Week 10: The z Test for a Population Proportion
Today it’s time for yet another test: the z test for a population proportion!
When Would You Use It?
The z test for a population proportion is used to determine if, in an underlying population comprised of two categories, the proportion of observations (in a sample) in one of the two categories is equal to a specific value.
What Type of Data?
The z test for a population proportion requires categorical (nominal) data.
Test Assumptions
- Each of the n independent observations is randomly selected from a population, and each observation can be classified into one of two mutually exclusive categories.
- It is recommended that this test is employed when the sample is not too small (n > 11).
Test Process
Step 1: Formulate the null and alternative hypotheses. The null hypothesis claims that the likelihood an observation will fall into Category 1 in the population is equal to a certain probability. The alternative hypothesis claims otherwise (that the population proportion for Category 1 is not equal to the value stated in the null).
Step 2: Compute the test statistic, a z-score. The test statistic is computed as follows:
Step 3: Obtain the p-value associated with the calculated z-score. The p-value indicates the probability of observing a sample proportion as extreme or more extreme than the observed sample proportion, under the assumption that the null hypothesis is true.
Step 4: Determine the conclusion. If the p-value is larger than the prespecified α-level, fail to reject the null hypothesis (that is, retain the claim that the probability of falling into Category 1 in the population is equal to the value specified in the null hypothesis). If the p-value is smaller than the prespecified α-level, reject the null hypothesis in favor of the alternative.
Example
The data for this example come from my n = 30 students from one of my STAT 213 labs. I want to test the hypothesis, based on my lab, that the proportion of students who come to lab for ALL the 213 labs (for this particular instructor) is 40%. We take attendance, so we know who’s there and who’s not for a given week (note, however, that I’m going to randomly select an attendance sheet from one of the weeks of lab, AND I actually never pay attention to what the proportion of students who show up is, so I’m really just guessing about 40%). So let’s do it! Set α = 0.05 and let π denote the proportion of individuals to come to lab.
H0: π = .4
Ha: π ≠ .4
Computations:
Since our p-value is (only slightly) larger than our alpha-level, we fail to reject H0 and claim that the population proportion of students who attend labs is, in fact, .4.
Example in R
dat = read.table('clipboard',header=F) #'dat' is the name of the imported raw data
#'dat' coded such that 0 = did not attend, 1 = attended
n = nrow(dat)
X = sum(dat)
p1 = X/n
pi1 = .4
z = (p1-pi1)/(sqrt((pi1*(1-pi1))/n)) #z-score
pval = (1-pnorm(z))*2 #p-value
#pnorm calculates the left-hand area
#multiply by two because it is a two-sided test
Old Habits Die Hard
Or not at all.
I’m a horrible person.
Claudia’s Big Walk: The Plan
Yo.
I want to see just how far I could go if given an entire day of walking (plus enough power on my iPod to get through it, haha).
I’ve wanted to do this since last summer, but I just didn’t get the chance (too busy with school stuff/moving/traveling and/or the weather was garbage). So hopefully this summer, once classes are out, I’ll be able to pull it off. I just need an “optimal weather” day, meaning not too freaking hot, not too windy, and (ideally) a little clouded over. Those days happen up here, but it’s just a matter of getting one in the summer when the daylight hours are longer.
ANYWAY, here’s my planned route for that day, whenever it comes. I chose these locations because a) they’re mostly all malls, which would serve as good stopping points to get water/go to the bathroom/re-charge the iPod if necessary; b) I know how to get to all of them; and c) I know the bus routes back to home from all of these locations, so if I end up getting stuck at one of them and not wanting to walk further, I can just grab a bus and get home that way.
Unrealistic? God, I don’t know. If I did this entire route, it wouldn’t take me 16:20 like Google says, ‘cause I walk quite a bit faster than their estimated walking time. But I probably would be slowing down near the end, haha. 49 miles is a lot. I suppose I can give it a try and see if I could do it!
WOO I AM PUMPED even though this isn’t happening for a few months at least.
What it’s Like to Read Lips
Sign language. This is why it’s important.
Which Philosopher would Fare Best in a Present-Day University?
DAMN STRAIGHT HE WOULD.
Man, I’d get a study group together right away. And by “study group” I mean “just Leibniz and me, somewhere quiet where he can do his genius stuff and I can guard him ‘cause he’s precious.”
I can’t help it, I’m obsessive. Seriously, if I was ever given the option to, say, time travel back to any year (and location) of my choice, I would with zero hesitation pick something involving Leibniz.
Witness the signing of the Declaration of Independence?
Nope.
See man first create fire?
Nope.
Observe the dinosaurs?
Nope.
Leibniz.
Eigenblogger 