Comments on: Too poor to buy a stats package!
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package/
Comments on Ask MetaFilter post Too poor to buy a stats package!Fri, 21 May 2010 10:16:00 -0800Fri, 21 May 2010 10:16:00 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Question: Too poor to buy a stats package!
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package
Free stand-alone stats programs for Mac and/or Windows that have (at a minimum) two-way ANOVA and linear regression capabilities? Barring that, good resources for learning R? <br /><br /> I'm a grad student working in a lab where most of our experiments are super-simple in design and require no test more complicated than a T-test (or a chi-squared test). Because I'm apparently the black sheep of the group, I set up several slightly more complicated experiments, all of which need to be analyzed using two-way ANOVAs. I have another tentative series of experiments in the pipeline that will require regression analysis. <br>
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Unfortunately, the only program on the lab's computers with any statistical functionality whatsoever is Excel. Extra-unfortunately, my advisor "upgraded" all the lab computers to Excel 2008, so I lost Excel's rudimentary statistical functionality with that switch. I don't mind doing t-tests and one-way ANOVAs/post-hoc tests by hand, but I'm probably going to screw up if I try to do four two-way ANOVAs and three linear regressions by hand. Not to mention that it will take a lot of time and effort doing what is essentially the sort of busywork for which computers were invented in the first place.<br>
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So... I'm trying to either find an easy-to-learn free program that will let me quickly and simply run my data analyses, or find good resources for learning R. I've been toying with the idea of learning R anyway, because there are existing packages for pretty much any analysis that I would ever need to do -- having no statistics package in my lab might just be the kick in the pants that I need.<br>
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Here are my limitations:<br>
1) I don't have any money, at all, to spend on anything whatsoever. I know that I could get pretty much any commercially-available stats package from the campus computing center for cheap, but even a $5 license fee is too expensive for me right now. My lab is also broke.<br>
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2) Lab computers are split down the middle between PCs running Windows XP and Macs, running whatever the latest version of OS X is . I have a senile MacBook and a fairly recent Dell Latitude (the Dell is running Windows Vista, which came pre-loaded and which I have been too lazy to change). Software doesn't need to be available for all these systems, but it should work in at least one of them.<br>
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3) I have extremely limited programming experience. (I spent the time that I *should* have spent taking comp sci and/or math courses taking extra biology electives, where I learned how to count rats humping each other in a dimly-lit room.) I don't need to learn enough to write new extensions in R, but I do need to learn enough to understand how the language works, and be able to use the packages that other people have written.post:ask.metafilter.com,2010:site.154493Fri, 21 May 2010 10:08:55 -0800kataclysmstatisticalsoftwarefreewarestatisticsstatspackagesrtwo-wayanovaresolvedBy: dfriedman
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215456
Excel 2007 for windows does linear regression. I know this because I just used it this morning. <br>
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I believe, but am not certain, that it also does ANOVA.<br>
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Further I know scientists and statisticians don't like Excel's statistical analysis tools for reasons that seem fairly abstruse to me.<br>
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Short answer: Excel will do what you want. <br>
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Long answer: There's probably something better out there for your uses. Have you experimented with Wolfram Alpha's web site?comment:ask.metafilter.com,2010:site.154493-2215456Fri, 21 May 2010 10:16:00 -0800dfriedmanBy: dfriedman
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215462
FYI: your problem with Excel may be that you need to have the Analyst Toolpak installed. See this for more info: http://www.google.com/search?q=excel+2007+anova&ie=UTF-8&oe=UTF-8&hl=en&client=safaricomment:ask.metafilter.com,2010:site.154493-2215462Fri, 21 May 2010 10:18:21 -0800dfriedmanBy: kataclysm
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215466
Excel 2007 will do what I want. Excel 2008 will not do what I want. Microsoft got rid of the VBA Analysis Toolpak when they released Office 2008.comment:ask.metafilter.com,2010:site.154493-2215466Fri, 21 May 2010 10:20:29 -0800kataclysmBy: eisenkr
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215470
If you're in graduate school in the sciences, I'd recommend jumping into R. I'm sure there's a way to jury rig Excel into running 2-way ANOVAs (I think I took a class once where it was an assignment), but is there any downside to moving to a real stats platform? I can't imagine that having extra stats knowledge is ever a bad thing in the sciences.<br>
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As for learning R, there were some great answers regarding previous asks of that question.comment:ask.metafilter.com,2010:site.154493-2215470Fri, 21 May 2010 10:21:29 -0800eisenkrBy: dfriedman
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215473
There are third party addins for xl 08: http://www.officeformac.com/blog/Now-Available--Data-Analysis-For-Excel-2008<br>
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another thought: try open office if you want a spreadsheet environment.comment:ask.metafilter.com,2010:site.154493-2215473Fri, 21 May 2010 10:23:28 -0800dfriedmanBy: k8t
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215479
torrent spss 11. It'll do what you need with no need to learn progamming.comment:ask.metafilter.com,2010:site.154493-2215479Fri, 21 May 2010 10:26:14 -0800k8tBy: chiefthe
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215497
How about a 30 day free trial of <a href="http://www.minitab.com/en-US/academic/semester-rentals.aspx">Minitab</a>?comment:ask.metafilter.com,2010:site.154493-2215497Fri, 21 May 2010 10:39:33 -0800chieftheBy: zenon
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215498
On the PC side the toolpac is built in - enabling add-ins is done through the Office Button | Excel Options | Add-Ins, which is where all Add-In management takes place. It is only the Mac's that something is different 2008(MAC) can have the same/similar tools as previous editions- you need to download a third party (ie: MS didn't want to deal with it anymore) nagware that should cover the basic analysis you are looking for. It's called StatPlus:mac LE (which preliminarily google searches found no working link) but I would just go with the PC version.<br>
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This is what R is for. <a href="http://www.r-project.org/">It's free</a>. You likely don't need special R packages for what you are doing (assumption!) so you should try it out - go with the PC version.<br>
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If you can, don't use Excel - it reportedly<a href="http://www.stat.uiowa.edu/~jcryer/JSMTalk2001.pdf"> has problems (PDF)</a> and perhaps more accessible <a href="http://en.wikibooks.org/wiki/Statistics/Numerical_Methods/Numerics_in_Excel">here</a> although MS does <a href="http://support.microsoft.com/kb/829215">claim it has fixed the issue.</a>comment:ask.metafilter.com,2010:site.154493-2215498Fri, 21 May 2010 10:39:35 -0800zenonBy: zenon
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215500
This PROBLEM is what..... (etc etc)comment:ask.metafilter.com,2010:site.154493-2215500Fri, 21 May 2010 10:40:18 -0800zenonBy: mandymanwasregistered
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215503
I'm teaching myself R right now--fuck those overpriced licenses for other programs! It was a little bit wtf this is a whole new language I can't deal with this at first, but that goes away faster than you think. I rely on <a href="http://www.statmethods.net/index.html">this guide</a> and <a href="http://www.ats.ucla.edu/stat/r/">this one</a> the most. I also keep a text document with a running list of my most frequently needed commands for easy reference.comment:ask.metafilter.com,2010:site.154493-2215503Fri, 21 May 2010 10:42:16 -0800mandymanwasregisteredBy: MadamM
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215584
Duuude use R! I promise it's super easy to get to the point where you will feel comfortable doing the kinds of tests you need. If you'd like, I can email you some of the material we used in my intro stats class. If you don't need to do anything very complicated, you don't really need a high-level understanding of R, just a few key commands that you can copy and paste every time you need them.comment:ask.metafilter.com,2010:site.154493-2215584Fri, 21 May 2010 11:20:31 -0800MadamMBy: MadamM
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215585
Also, in my opinion the R interface is much better on OSX than Windows.comment:ask.metafilter.com,2010:site.154493-2215585Fri, 21 May 2010 11:21:28 -0800MadamMBy: thissideofdead
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215587
Check out <a href="http://gretl.sourceforge.net/">gretl</a> it was the stats package that was used in my econometrics class last semester. It has the ANOVA model but don't know about the two way ANOVA model. Open source so its at least worth a look.comment:ask.metafilter.com,2010:site.154493-2215587Fri, 21 May 2010 11:22:20 -0800thissideofdeadBy: knile
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2215589
For the R route, <a href="http://www.ualberta.ca/~baayen/publications/baayenCUPstats.pdf">This is a direct link to a PDF of Harold Baayen's book Analyzing Linguistic Data</a> which is the go-to guide around my researchworld. I am working my way through it now.comment:ask.metafilter.com,2010:site.154493-2215589Fri, 21 May 2010 11:23:18 -0800knileBy: en forme de poire
http://ask.metafilter.com/154493/Too-poor-to-buy-a-stats-package#2217243
Yes, R is going to be your friend on this one. Some quick R pointers:<br>
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The function <tt>lm</tt> (linear model) is going to be really useful for you. Regression, ANOVA, and ANCOVA are all basically just instances of linear models.<br>
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<tt>yourmodel <- lm(Y ~ a + b + c + 1)</tt> fits the linear model <tt>Y = Aa + Bb + Cc + intercept</tt> (the + 1 is optional, I think). Change the <tt>+1</tt> to a <tt>-1</tt> for no intercept. Type <tt>summary(yourmodel)</tt> to get coefficient estimates, t-statistics, and the associated p-values for each coefficient. If A, B, and C are continuous variables, you've just done a multiple regression; if they are factors you have an ANOVA; if you have some of each you have an ANCOVA. Bam!<br>
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For interactions, you would use the asterisk, e.g., <tt>lm(Y ~ a*b + c + 1)</tt>, which fits a model with main effects for a, b, and c as well as an interaction effect for a and b. To get just the interaction and no main effects, use the colon: <tt>lm(Y ~ a:b + c + 1)</tt> would give you just the interaction between a and b with no main effects, and the main effect of c.<br>
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A few other useful functions:<br>
<tt>read.table</tt> and <tt>read.csv</tt> for reading spreadsheets<br>
<tt>write.table</tt> and <tt>write.csv</tt> for saving them<br>
<tt>factor</tt> makes a vector of characters into a factor that you can use for <tt>lm</tt><br>
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Here's a potentially helpful <a href="http://www.amazon.com/exec/obidos/ASIN/0387954759/metafilter-20/ref=nosim/">book</a>. Previously there was an excellent <a href="http://www.metafilter.com/89236/The-R-Project-for-Statistical-Computing">FPP about R</a>.<br>
</tt></>comment:ask.metafilter.com,2010:site.154493-2217243Sat, 22 May 2010 23:35:26 -0800en forme de poire