Ask MetaFilter questions tagged with math
http://ask.metafilter.com/tags/math
Questions tagged with 'math' at Ask MetaFilter.Mon, 29 Jun 2015 21:03:24 -0800Mon, 29 Jun 2015 21:03:24 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Help me create a player ranking system for a game
http://ask.metafilter.com/282247/Help%2Dme%2Dcreate%2Da%2Dplayer%2Dranking%2Dsystem%2Dfor%2Da%2Dgame
I want to create a ranking system for a game that will be more refined than just ranking the users in order 1, 2, 3, etc. I have a game, the participant number is variable and can go into the thousands. I already have a point system where I can rank them in order (1- however many participants there are, based on how many points they have obtained in the game). But ranking them 1, 2, 3, etc. is boring (and also communicates too much about how they are doing in relation to other players).<br>
<br>
I want to instead create an artificial number for the ranking. So similar to a credit score, I want to take their actual ranking, do some math wizardry, and then tie it to a different number on a scale, similar to how a credit score can go from 300-850. Bonus points if you're able to give me some formula that lets me choose different ranges of numbers.tag:ask.metafilter.com,2015:site.282247Mon, 29 Jun 2015 21:03:24 -0800banishedMath equation problem
http://ask.metafilter.com/280732/Math%2Dequation%2Dproblem
Asking for a friend:
I have a question about how to work out a student's exam mark.
Unit 1 is worth 60%, Unit 2 is worth 40%. Both units are marked out of 80. For example, a student scores 67/80 on unit 1 and 69/80 on unit 2. What is their overall mark?
Thanks for any help!tag:ask.metafilter.com,2015:site.280732Thu, 28 May 2015 05:31:25 -0800charlenIs there a name for this shape?
http://ask.metafilter.com/280681/Is%2Dthere%2Da%2Dname%2Dfor%2Dthis%2Dshape
What would you call the shape of the two-dimensional outline of the two stones (cabochons)<a href="http://imgur.com/tyIYnbv"> circled in red in this picture</a>? The stones don't appear to be "perfect" but they are approximating something that I'm sure should have a name.<br>
<br>
Just like I can tell that the outline of <a href="http://www.rpmjewellery.com.au/shop/product.php?productid=17585">this piece</a> is a <a href="http://en.wikipedia.org/wiki/Reuleaux_triangle">Reuleaux triangle</a>, I'd like to be able to name (and perhaps even mathematically generate) this curved parallelogram type shape.<br>
<br>
The closest I've found is the shape formed by two sine waves that are out of phase like <a href="http://imgur.com/QHXFrBM">in this picture.</a>tag:ask.metafilter.com,2015:site.280681Wed, 27 May 2015 06:48:30 -0800sparklemotionMy Math/Excel Ignorance is Showing
http://ask.metafilter.com/279858/My%2DMath%2DExcel%2DIgonrance%2Dis%2DShowing
In three cells in a single column in Microsoft Excel, I'd like to be able to input a number in the bottom cell, have the middle cell calculate what a 6% sales tax on the figure below it is, and provide the amount before that 6% tax in the top cell.
Any help will be appreciated. The last math class I took was 44 years ago and I didn't pay much attention in that one.tag:ask.metafilter.com,2015:site.279858Fri, 08 May 2015 14:34:19 -0800imjustsayingAnything like the Harvard Extension School in the DC area?
http://ask.metafilter.com/279569/Anything%2Dlike%2Dthe%2DHarvard%2DExtension%2DSchool%2Din%2Dthe%2DDC%2Darea
I’m likely relocating to Washington DC this summer and I'm looking for somewhere where I can take Linear Algebra and a few other undergraduate math and statistics classes in Fall 2015 and Spring 2016 as a non-degree student. I currently live in Cambridge, and I've been taking courses through the (excellent) <a href="http://www.extension.harvard.edu/">Harvard Extension school</a>, which essentially offers open-enrolment versions of many of Harvard’s undergraduate courses. Unfortunately, they don't seem to have online versions of many of their advanced math courses, so I’m looking for an institution in DC where I can keep taking courses as a non-degree student as I apply for masters programs in Stats and CS.<br>
<br>
Obviously there are many schools in DC, but from my limited googling it’s not clear to me which one is likely to offer the best options for someone in my shoes. If the instruction is good, I have nothing against night schools or community colleges, but I don't know which ones I should be looking at. I will have a very flexible work schedule, so taking courses during the day would also not be a problem. <br>
<br>
Thanks in advance!tag:ask.metafilter.com,2015:site.279569Sat, 02 May 2015 12:29:07 -0800dyslexictravelerThe Mathematics Of Time
http://ask.metafilter.com/279238/The%2DMathematics%2DOf%2DTime
So I have a few years to kill and I'd like to spend them fully understanding what physicists and mathematicians know about time. I'm not looking for any sort of summary, I want to understand the math from the bottom up. I once caught my father going through the <em>Annus Mirabilis</em> papers with a red pen; that's the sort of proficiency I have in mind. Unfortunately my physics and calculus largely left off at the end of Freshman year, so I have a ways to go. I'm looking for some sort of hierarchy of the form:<br>
<br>
In order to understand the math for Special Relativity you'll need to understand Z<br>
In order to understand Z you'll need to understand X and Y<br>
In order to understand X you'll need to understand U, V, W<br>
<br>
Etc. I realize it's not as simple as a straight line, but that's the general idea.<br>
<br>
I'd also like to find such a chart for the math that goes into Quantum Physics.tag:ask.metafilter.com,2015:site.279238Sat, 25 Apr 2015 17:57:26 -0800Tell Me No LiesAm I doing compound interest wrong?
http://ask.metafilter.com/279135/Am%2DI%2Ddoing%2Dcompound%2Dinterest%2Dwrong
I'm hoping Metafilter can help me with a stupid math question, but one that's bothering me about how I was taught to compound interest versus some numbers I'm reading/hearing online about a Supreme Court case. Here's the gist. I got lost in the Wikipedia mindhole this afternoon and ended up at <em><a href="https://en.wikipedia.org/wiki/United_States_v._Sioux_Nation_of_Indians">United States v. Sioux Nation of Indians</a></em> where I saw this:<br>
<blockquote>Finally, under its new authorizing statute, the Claims Court held the Sioux had suffered a taking cognizable under the Fifth Amendment, and were entitled to the value of the land as of the 1877 taking which was $17.1 million, the value of gold prospectors illegally took out of the land computed at $450,000, and 100 years' worth of interest at 5% per year which would be an additional $88 million.[18]</blockquote><br>
In my head, though, that number seemed...wrong. I was taught annual interest compounded with a formula of B_n = P*(1+i)^n. The balance at year n is the principal times 1+i to the n. So, I plugged into my calculator and I got that 100 years of 5% annual interest on ~$17.5 million is ~$2.3 billion including the principal. The only way I could get to ~$88 million of interest is ~37 years of compounding.<br>
<br>
Can someone here help me? This is either an "I don't understand math" or "I can't read the court opinion" answer.tag:ask.metafilter.com,2015:site.279135Thu, 23 Apr 2015 10:07:15 -0800FortranExorcizing the devil from the details
http://ask.metafilter.com/279108/Exorcizing%2Dthe%2Ddevil%2Dfrom%2Dthe%2Ddetails
I'm currently studying undergraduate math and though the concepts are clear, I lose a lot of marks through carelessness or small errors. Please help me pick up on/avoid these better. I am sure I lack discipline. As a fairly bright sort I am accustomed to doing math in my head, which no longer cuts it at university level. Trying to hold it in my head for more involved problems results in small errors like losing a minus sign or slight number errors which throw the whole thing awry. I also have trouble mixing up capital and lower-case letters, which doesn't help.<br>
<br>
The question is twofold: Faced with a similar detail-demanding discipline, what methods do you use to avoid errors? Similarly, how do you -find- errors after the fact?tag:ask.metafilter.com,2015:site.279108Wed, 22 Apr 2015 19:33:16 -0800solarionBusiness math word problem: calculating salary through "growth tiers"
http://ask.metafilter.com/279076/Business%2Dmath%2Dword%2Dproblem%2Dcalculating%2Dsalary%2Dthrough%2Dgrowth%2Dtiers
I'd like some help coming up with a formula for calculating annual salary increases. The idea is that a given job description will have two "growth tiers", through which an employee's salary will increase at different rates, and beyond which their salary cannot increase further (except for cost-of-living adjustment). There's also a "base growth factor", which is determined by individual employee performance--e.g. 10% for a stellar employee, 6% for a good employee, etc. Lots more inside. So here's an example: Let's say we have a Field Engineer, Amazing Ashley, who's currently making $63,000 (in 2015 U.S. dollars). The 2015 growth tiers for the Field Engineer position are the following:<br>
<br>
$60,000: minimum salary<br>
$60,000 - $72,000: first, "quick" growth tier<br>
$72,001-$84,000: second, "slow" growth tier<br>
$84,001 and above is "maxed"--no further growth possible except cost-of-living adjustment<br>
<br>
Ashley has done really well at her job in 2015, so in early 2016, at annual review time, she's assigned a "base growth factor" of 10%. Ashley's salary will be increased by the unmodified "base growth factor" until it hits the top of the first growth tier ($72K). It will then continue to increase through the second growth tier, but at a modified factor of 5% (half her base growth factor).<br>
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I also want to account for cost of living. Let's peg this at 1.7%. So Ashley's new 2016 salary would be something like (63000 + 6300) 1.017 = $70,478 (I think?).<br>
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Easy enough--because she hasn't crossed into the second growth tier yet. But the 2017 raise will be trickier. And here's the other thing: the growth tiers also adjust to account for increased cost of living. So while the 2015 tier caps for Field Engineer are $72,000 and $84,000, the 2016 numbers will be slightly more: $73,224 and $85,428.<br>
<br>
Assuming Ashley continues to do amazingly at her job (10% base growth factor), what will her 2017 salary be? 2018? 2023?<br>
<br>
And what about Decent Denise? (Sorry Denise.) She's a Field Engineer making $61,500 in 2015 who'll be given a base growth factor of 6% at her 2016 review, which means her new 2016 salary will be $66,298 (I think?). Assuming she remains merely decent, what is her 2020 salary?<br>
<br>
So there you have it. I don't think I'm fully grasping the issue, so my presentation of the information might be bad and might be based on some wrong assumptions. There may also very well be "real" math/statistics terms for the concepts I'm describing, but I don't know them (which might be why I'm having trouble googling this one). If you know them, please set me straight.<br>
<br>
Thanks in advance everyone!tag:ask.metafilter.com,2015:site.279076Wed, 22 Apr 2015 09:43:15 -0800Mr. ProfessionalBooks/review of high school math for former math major, current tutor
http://ask.metafilter.com/276837/Books%2Dreview%2Dof%2Dhigh%2Dschool%2Dmath%2Dfor%2Dformer%2Dmath%2Dmajor%2Dcurrent%2Dtutor
I need book recommendations two categories:
1) for myself for review (that are somewhere between high school text books and Spark notes)
2) just straight up textbooks for high school math (algebra i, geometry, algebra ii, trigonometry, pre-calculus) Hello! <br>
<br>
Currently I tutor one student in Algebra ii. Although i have been able to eke it out, i would like a more comprehensive review of maths so i can do a better job. Part of the problem is my student doesnt have a text book and the teacher seems to randomly wander around in the algebra ii world. Another part of the problem is it has been many years since i have done math. The sad thing is, even though i have my undergraduate degree in math, so i really should be able to connect things better than i currently am, my brain has swiss-cheesed its math knowledge. I really like tutoring and i really like math, so i would like to tutor more. To do this, I need to do some serious review. I have been trying to do this, but i have run into a few problems:<br>
<br>
<br>
Regarding review books:<br>
As i said, I need something between the high school textbooks and Spark notes. I really wish Spark notes were enough, but my brain apparently needs more help re-connecting concepts than those provide. I have gone to bookstores to check out their review books (___ for dummies, barrons, etc) for my student, and they seemed a little too long-winded for me (although if you guys recommend them, i will give them another shot)! I know it is whiny, but i get super bored trying to get myself to read about all this math targeted to current struggling high school students. I have tried to force myself to read, say, Barrons, but my brain revolts. I hope that makes sense.. Truthfully, i do not know exactly what i need/want, which i think is part of the problem. I can only really afford to buy one review book for each subject otherwise i would just buy a few books at barnes and noble and see which one works best (and I _have_ checked libraries and thrift stores and used bookstores for review books).<br>
<br>
<br>
Regarding textbooks:<br>
I would really like to get one textbook of each subject, so i can see at what pace they teach concepts, have access to appropriate level problems, etc. I have checked many libraries, goodwills, salvation armies, misc thrift stores, the strand, and misc used bookstores and found 0 textbooks for my hours of looking. I know i can order them online through like amazon or a used textbook site, but the problem there is i dont know which books are good/bad and i dont want to have to buy a few books of each subject to find ones i am happy with. <br>
<br>
<br>
On a side note, my brain has a really bad filter as to what things are more important than other things (i have add), which is why the seemingly easy task of choosing books is for difficult to me. Also, if you guys have any random advice you would like to impart to me, please feel free! Thank you guys for any help you provide and i hope this all made sense.tag:ask.metafilter.com,2015:site.276837Thu, 05 Mar 2015 15:31:15 -0800miss so and soLooking for a blogging platform that handles equations and code
http://ask.metafilter.com/276540/Looking%2Dfor%2Da%2Dblogging%2Dplatform%2Dthat%2Dhandles%2Dequations%2Dand%2Dcode
My friend and I are starting an academic blog. We will be posting equations and code snippets (mostly MATLAB), and are looking for a blogging platform that will allow us to enter them easily and display them nicely. Do you have any suggestions on what we should use?tag:ask.metafilter.com,2015:site.276540Fri, 27 Feb 2015 11:58:42 -0800tickingclockHow can I quantify these fitness scores?
http://ask.metafilter.com/276406/How%2Dcan%2DI%2Dquantify%2Dthese%2Dfitness%2Dscores
Hey math/fitness nerds. I'm working on a pet project. I'm trying to quantify general fitness levels across a population based on a few different scores. I have the tests, but need help setting up the values of each score. This question is not about the validity of these tests, it's about numbers. I'm open to discussion about the tests, but not here. (Please mail me if you have strong opinions about the tests.) This is strictly a math question.<br>
<br>
I'm trying to give each score a value out of 100 so the scores can be displayed in a radar-style graph.<br>
<br>
The tests are as follows:<br>
Overhead squat mobility test. Score from 1-5 points. (5 = 100%)<br>
1.5 mile run test time. 10 min 30s = 100% (630 seconds.)<br>
500 meter ergometer row test time. 1 min 37 s = 100% (97 seconds)<br>
1 Rep Max Deadlift. A weight of 1.75 bodyweight = 100%.<br>
<br>
So here's an imaginary test subject:<br>
Male<br>
185 lbs<br>
Squat evaluation = 4/5<br>
1.5 mile run time = 12 minutes or 720 seconds.<br>
500 meter row time = 2 min or 120 seconds.<br>
1RM Deadlift = 225 lbs. At 185 lbs he'd need to pull 323.75 lbs.<br>
<br>
So I'd like to know the best way to put each of the scores at a 100 point value. This is slightly tricky for me as obviously higher times would be worse than lower times.<br>
<br>
Could someone help me with the formula in excel so I could just drop the scores into a spread sheet and get some answers? This is a basic math question not really an excel question. I know it's the sort of thing that's dead easy for some people but fairly mystifying for me.<br>
<br>
To use the above examples:<br>
Goal time for 1.5 miles is 10 minutes and 30 seconds. (630 seconds.) The subject ran 1.5 miles in 720 seconds. How can I set up the formula so that 720 seconds is scored out of 100 on a scale that uses 630 as a perfect score of 100 with anything larger being a worse score?<br>
<br>
Thanks.tag:ask.metafilter.com,2015:site.276406Wed, 25 Feb 2015 02:42:52 -0800TelfSomething more interesting than :(){ :|:& };:
http://ask.metafilter.com/276254/Something%2Dmore%2Dinteresting%2Dthan%2Dand
What are some fun, computationally intensive tasks for my new computer to do? I just got a new computer and I feel like making it work really hard. What are some things to do? Assume I can program, and that I can install most languages, libraries, and software packages (including MATLAB and Mathematica). 4 cores, NVIDIA GPU. I'm leaving this deliberately broad, but here are some loose criteria (all of which are optional):<br>
<br>
<ul> <br>
<li>doesn't require too much investment in specialist libraries or domains of knowledge</li><br>
<li>results are pretty, lots of colors</li><br>
<li>learning how to do it might be somewhat educational</li><br>
<li>if results not visual, they are interesting on their own terms</li><br>
</ul><br>
<br>
It has already occurred to me to draw a very, very high resolution picture of the Mandelbrot set, but I was hoping you all would have something more original. Do not limit yourself to rendering mathematically interesting bitmaps!tag:ask.metafilter.com,2015:site.276254Sat, 21 Feb 2015 15:15:26 -0800vogon_poetProbability distributions and their practical applications
http://ask.metafilter.com/276170/Probability%2Ddistributions%2Dand%2Dtheir%2Dpractical%2Dapplications
I am looking for a resource that lists probability distributions and their common real-world applications. For example, I'd expect to see: Lognormal - daily returns in the stock market. Poisson - failure rates for mechanical equipment, ... The closest I can find is this wiki entry. http://en.wikipedia.org/wiki/List_of_probability_distributions<br>
<br>
Ideally this would be a handbook which includes applications in as many fields as possible (biology, actuarial, physics, etc.) Does this resource exist?tag:ask.metafilter.com,2015:site.276170Thu, 19 Feb 2015 13:19:17 -0800wivyHelp me do some math?
http://ask.metafilter.com/275828/Help%2Dme%2Ddo%2Dsome%2Dmath
Help me do some math? I have four buckets. I need to fill each bucket with a certain number of widgets (no more, no less) from a pile. How many possible variations exist?<br>
<br>
BUCKET ONE:<br>
- Holds 4 widgets.<br>
- There are 4 widgets to choose from.<br>
<br>
BUCKET TWO:<br>
- Holds 3 widgets.<br>
- There are 7 widgets to choose from.<br>
<br>
BUCKET THREE:<br>
- Holds 4 widgets.<br>
- There are 13 widgets to choose from.<br>
<br>
BUCKET FOUR:<br>
- Holds 2 widgets.<br>
- There are 10 widgets to choose from.<br>
<br>
I'm sure I learned how to do this in school, but that knowledge has long since left my brain. If you could show me how you do the calculation in addition to giving the answer, I'd appreciate it!tag:ask.metafilter.com,2015:site.275828Thu, 12 Feb 2015 08:25:00 -0800NotMyselfRightNowKeeping on top of the snowstorm -- does it really matter?
http://ask.metafilter.com/275673/Keeping%2Don%2Dtop%2Dof%2Dthe%2Dsnowstorm%2Ddoes%2Dit%2Dreally%2Dmatter
I am in the snowy state of Massachusetts and avoiding my next foray out to shovel. Plus, spouse and I slightly disagree on how often we really need to go out and shovel. Does it really save time to shovel every few hours throughout the storm? I have a suspicion that it doesn't really save time, and that we be just as fine waiting until the end of the snowstorm -- is there a way to think this through mathematically to find a good answer?tag:ask.metafilter.com,2015:site.275673Mon, 09 Feb 2015 09:40:37 -0800lillygogGiant numbers (Ex: how many primes are smaller than the largest known?)
http://ask.metafilter.com/275591/Giant%2Dnumbers%2DEx%2Dhow%2Dmany%2Dprimes%2Dare%2Dsmaller%2Dthan%2Dthe%2Dlargest%2Dknown
Many sites say that the largest known prime is "2^57,885,161 − 1, a number with 17,425,170 digits." Given this and well known research about the density of primes, I think it's at least possible to estimate the number of primes between 1 and 2^57,885,161 − 1. But I don't know how to do this myself.
I really want the answer to this one (the order of magnitude at least), but I've got lots of these, and I'd ideally like more cool ones. :) For context, I'm making an activity for high school students in an afterschool math program. The activity is aimed at understating really big numbers, and this part of the program (4 sessions) is focused on bijections and infinties, with a theme of how mathematicians think about topics that are too large or abstract to handle with intuition, and for how mathematicians make choices that shape what the mathematics we study looks like. For this activity in the first session, in addition to many mathematical examples, I want to include some examples from life and things in the middle (like the limits of modern computation.)<br>
<br>
The activity is not to calculate these quantities, but rather to estimate them to the extent that they can be ordered least to greatest.<br>
<br>
I would greatly appreciate<br>
A) Suggestions for additions to this list<br>
B) Estimations for new additions or for the items listed below with question marks<br>
C) Corrections to this list if you think one of my listed estimations is at the wrong order of magnitude <br>
D) An estimate for the primes question in particular. <br>
<br>
THANKS!<br>
<br>
----------------------------------------------------------------<br>
<br>
The list so far:<br>
<br>
* The number of primes between 0 and 2^57,885,161 − 1<br>
* If two 'opponents' at Go are actually collaborating to make the game as long as possible, how many turns might the game last (on a 19x19 board)? (???)<br>
* The number of different chess games for which the board never returns to a previously experienced state. (???)<br>
* The approximate number of atoms in everything living on the earth (???)<br>
<br>
* The approximate circumference of the earth in miles (~10^4)<br>
* The approximate number of sheets of paper in a stack as tall as the height of the Transamerica Pyramid in SF (~10^6)<br>
* The approximate number of seconds in a human life (~10^9)<br>
* The approximate number of people in the world right now (~10^10)<br>
* The approximate number of neurons in a human brain (~10^11)<br>
* The approximate number of seconds between now and when a dinosaur last lived (~10^15)<br>
* The approximate number of ants in the world right now (~10^16)<br>
* The approximate number of calculations that can be done by the world's current fastest computer (The Tianhe-2 supercomputer) in 1 minute (~10^18)<br>
* The approximate number of stars in the universe (~10^30)<br>
* The approximate number of atoms in the earth and everything on it (~10^50)<br>
* The approximate number of different ways a deck of 52 cards might be shuffled (~10^68)<br>
* The approximate predicted number of atoms in the universe (~10^80)<br>
* The approximate number of rabbits that would exist in the universe after a year if, starting with 2 rabbits, ever day, every pair of rabbits alive mate and produce 6 offspring, and no rabbits ever die. (~10^219)tag:ask.metafilter.com,2015:site.275591Sat, 07 Feb 2015 05:40:29 -0800ch3coohDouble checking math for the gaslit
http://ask.metafilter.com/275560/Double%2Dchecking%2Dmath%2Dfor%2Dthe%2Dgaslit
A math problem followed by an issue with the boss. <br>
The math: my boss gives me 50 picomoles per microliter of human serum albumin as standard, with a molecular mass of about 66400 grams per mole. I loaded, as per his instructions, 100 microliters of that. I loaded 100 micrograms (in 100ul again) of keyhole limpet haemocyanin which has a molecular mass of 390000 grams per mole. Unless I'be goofed in the math, I loaded 332 micrograms (250 picomoles total) of HSA standard he ordered me to load. On the sample run, I loaded 100ug (39 picomoles total) of KLH. If that checks out with everyone else, awesome, please continue below and help me. If it doesn't then the following is still an issue but of a different flavor. <br>
<br>
So there was a problem with the equipment (sample loop on the HPLC) that caused the sample of KLH to be lost. My boss blows up at me and whether he was spitting because he was so worked up or because he was chewing again, it was still a sight this chemist wishes to never see again. He was angry because I had spent two days on the KLH sample and wasted it all (ignoring my feeble "but I saved 10ul for the mass spec analysis after this looked good by RP-HPLC!"), burning time, money (<$100), and used 300% of the HSA mass to boot. "Brainlessly" "thoughtless" "stupid" etc all made appearances here.<br>
<br>
But the math doesn't bear out, I used 1/3 the mass and was in no danger of overloading the column as he was going on about. It's a shame the sample was lost but I don't feel like there was any way for me to catch that before it happened. <br>
<br>
So the KLH is a side project that I'm doing while waiting for the real work to pick up again. I've also brought a second HPLC back from the dead, organized things in the lab, prepped for the real work starting up again next week, successfully explored a new method to augment the real work, and read whatever I could get my hands on about HPLC (which I had no direct experience in until three months ago, I was an Acta/FPLC guy and self taught this while waiting for the product rep to show up and give lessons, which never happened). I feel like in the three months I've worked here, I've done good stuff for someone who went from life science lab to a mass spec/organic lab. <br>
<br>
There has been one time when I did do something stupid (miscut a gel and let the labels on the tubes run off in the presence of acetone) and plenty of blowups over tiny things. Every time, he says something along the lines of, "I'm not angry just..." or "I'm not pissed with you but..." which is patently not the case. He was angry, that he calmed down 30s later while we were still talking isn't the same as not having exploded in the first place. He isn't always angry but that doesn't really matter when the stress from walking on eggshells around him accumulates. <br>
<br>
He is my point of contact here as a contractor but weirdly I was hired by another department to work for him. I'm around this other department, am invited and attend their lab meetings, and am on good terms with their boss (my actual boss?). So I want to send my angry point of contact a polite but firm letter addressing the math issue and how the stress stemming from his outbursts is not acceptable to me. I don't want to talk about it face to face at first as, well, I am not the strongest lily in the wilting lily garden, I would rather set the tone without having to be a strong confident speaker that doesn't get railroaded by outbursts and excuses. Would that work? Are there any other lines of approach people would suggest? If this doesn't get better, should I go talk to other-department boss, the budget of whom I fall under? <br>
<br>
I'm strangely not afraid, career wise. It's only been three months but I've self taught the industry standard instrument to what I think of as a remarkable degree (making my own programs that work, confirming separations by gel, optimizing purification). My current contract gives me two weeks pay on leaving (going to double check this in case things go way south way fast) and I live in the DC area, so a fair number of jobs for HPLC fluent life scientists. <br>
<br>
This is so weird for me. Thanks for the help in advance everyone!tag:ask.metafilter.com,2015:site.275560Fri, 06 Feb 2015 12:38:19 -0800AnonymousLearning math online
http://ask.metafilter.com/275385/Learning%2Dmath%2Donline
I want to learn math. I signed up for Khan Academy and I like the format a lot. I really like that there are short lessons that I can complete, and that the software automatically checks the answers and lets me continue when I completed a string of 5 good answers in a row (or something similar). I don't like the video explanations though. I'm just not a video person, I learn much better from text. Is there something like Khan Academy where you can do math exercises online but where the explanation is in text?tag:ask.metafilter.com,2015:site.275385Tue, 03 Feb 2015 03:38:30 -0800blubI know enough calculus to think of the question but not the answer
http://ask.metafilter.com/275362/I%2Dknow%2Denough%2Dcalculus%2Dto%2Dthink%2Dof%2Dthe%2Dquestion%2Dbut%2Dnot%2Dthe%2Danswer
You want to walk 10 blocks north and 10 blocks east. It would be shorter to walk along the hypotenuse, but the same distance to walk 1 block north, then 1 block east, then 1 block north, etc. it seems that if the blocks were infinitesimally short, it would approximate the hypotenuse, but alas, walking 10 blocks in one direction and then 10 blocks in the perpendicular direction is the same as dividing it up. What gives?tag:ask.metafilter.com,2015:site.275362Mon, 02 Feb 2015 12:58:13 -0800i_am_a_fiestaHow do I draw like MC Escher?
http://ask.metafilter.com/275144/How%2Ddo%2DI%2Ddraw%2Dlike%2DMC%2DEscher
I'd like to understand how Escher made his architectural illusion drawings so I can model similar environments in 3D and then use those models to draw my own creations out on paper. How do I even get started? Since I was a kid I was fascinated by MC Escher's impossible architecture drawings. I particularly loved the infinite waterfall, endless stairs, and drawings where there are warped or overlying perspectives where you are looking up and down at the same time.<br>
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It occurred to me recently that I could MAKE these sort of images myself.. if I only knew how. I have a fair amount of art training and have lots of ideas for what things could look like and what sort of odd creatures I could populate them with but zero idea on how to actually get started. Most books on Escher I have read don't really include any detailed information on how he actually planned and created his images, only vague allusions to grid paper and models that he used.<br>
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My question is in several parts. <br>
1. How do I understand perspective and the perspective tricks underlying optical illusions? Most books on learning art and drawing perspective have been on basic 1, 2, and 3 pt perspective which is not really what I want to learn at all. Is there a good book on understanding warped perspectives and/or the visual basis of his sort of optical illusions? Looking for good books on understanding/creating optical illusions has been rather fruitless as well.<br>
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2. How do I model Escher-esque environments in 3D so I can then draw them? I'm willing to learn whatever 3D program (I only know 2D Adobe programs right now) that could get the basic forms down (mostly to model arches, stairways, and etc) but I haven't the foggiest idea on which would be most suitable. I know Escher illusions only "work" in 2D, so they can't really be modeled properly in 3D. The 3D models would only look right from certain angles. But the goal would just be to output some kind of limited shading 3D rendering that I can then draw over.<br>
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So: Is there a simple 3D program that includes perspective grids and the like that you can fiddle with? Is there even options in 3D programs for that? Is there a 3D program that can do isometric views? Which 3D programs could do this that aren't hard to learn?<br>
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3. Once upon a time I used Google Sketchup. Could Sketchup be used in this way? <br>
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I'm honestly flummoxed here on how to even begin or what to even research, so any information or suggestions at all would be highly appreciated.tag:ask.metafilter.com,2015:site.275144Wed, 28 Jan 2015 21:35:22 -0800everyday_naturalistSesame Street has me flummoxed
http://ask.metafilter.com/274708/Sesame%2DStreet%2Dhas%2Dme%2Dflummoxed
Sesame Street, when naming parts of shapes, consistently talks about the number of sides and the number of angles. For example a hexagon has six sides and six angles. This makes me crazy. I thought the pointy parts were "corners" or something like that. Doesn't a shape have infinite angles? If any three points can form an angle? Does 180 degrees not count as an angle? Isn't corner a more precise word?tag:ask.metafilter.com,2015:site.274708Tue, 20 Jan 2015 04:34:30 -0800OwowthathurtsHow to Tell Excel to Evaluate Last Three Months (NOT Last 90 Entries)
http://ask.metafilter.com/274661/How%2Dto%2DTell%2DExcel%2Dto%2DEvaluate%2DLast%2DThree%2DMonths%2DNOT%2DLast%2D90%2DEntries
I have an Excel spreadsheet I use to track glucose readings. There’s a value diabetics use called “A1C” which looks at the last three months of readings. It's based on a blood test, but can be estimated by averaging your readings for the last three months. I try to track every day, but I can’t reliably say “look at the last 90 values” – so I’m wondering how to set up a formula to tell it to only look at readings going back 90 days, not necessarily 90 readings. More inside. The formula to convert a glucose reading to an A1C value is =((<i><b>[value]</b></i>+77.3)/35.6). So converting an individual reading isn’t a problem.<br>
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But, basically, I’d like to create a new column for my spreadsheet which gives me a sort of running A1C average – always looking back three months from the current entry and telling me what the average of the last three months of readings would be. But, as said above, I can’t tell it to merely look back 90 entries, since if I missed a few days or a weekend, I don’t want it to look back further.<br>
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The dates are kept in column A, the time in column B, the reading in column C.<br>
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It'd be preferred not to use VBA to solve the issue, if that's possible.<br>
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Any help would be appreciated.tag:ask.metafilter.com,2015:site.274661Mon, 19 Jan 2015 08:18:09 -0800WCityMikeChaos Theory Explained for Non-Math People?
http://ask.metafilter.com/274584/Chaos%2DTheory%2DExplained%2Dfor%2DNon%2DMath%2DPeople
My curiosity whetted by the first few paragraphs (and double pendulum illustration) of <a href="http://en.wikipedia.org/wiki/Chaos_theory">the Wikipedia entry</a>, I want to learn as much and as deeply about chaos theory as possible without needing to know mathematics. Also interested in philosophical implications. Videos? Books or apps or web sites? My math may be weak, but I'm otherwise intelligent, so I'd prefer something much more thorough than, say, "Through the Wormhole" (I realize the math limitation's a huge hindrance, though).tag:ask.metafilter.com,2015:site.274584Sat, 17 Jan 2015 09:49:58 -0800Quisp LoverMultiplication and division resources for a 1st grader
http://ask.metafilter.com/274540/Multiplication%2Dand%2Ddivision%2Dresources%2Dfor%2Da%2D1st%2Dgrader
My first grader is asking about multiplication and division. Where do I start? He does well in math at school. His class is up to adding double-digit numbers like 50+8, and three "partners" of single digit numbers.<br>
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He asked me about multiplication a couple months ago, and I got him a multiplication table and tried to explain it as best I could. Then last night he asked me to explain division. I did what I could with the forks and straws on the dinner table, but realize I suck at teaching, especially math.<br>
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What are some good books, apps, websites I can use to introduce him to multiplication and division? Thanks!tag:ask.metafilter.com,2015:site.274540Fri, 16 Jan 2015 12:07:08 -0800DakotaPaul