% Writing beautiful and reproducible slides quickly
% Yihui Xie
% 2012/04/30

Why

• after you finished typing \documentclass{beamer} and \title{}, I have finished my first slide with markdown
• much less commands to remember, e.g. to write bullet points, just begin with a dash “-” instead of \begin{itemize} and \item; how things can be simpler?
• I know you want math to show you are a statistician, e.g. \( f(k)={n \choose k}p^{k}(1-p)^{n-k} \)
• you do not need to maintain output – only maintain a source file
• HTML5/CSS3 is much more fun than LaTeX

A bit R code

head(cars)

##   speed dist
## 1     4    2
## 2     4   10
## 3     7    4
## 4     7   22
## 5     8   16
## 6     9   10

cor(cars)

##        speed   dist
## speed 1.0000 0.8069
## dist  0.8069 1.0000

Graphics too

library(ggplot2)

## Error: there is no package called 'ggplot2'

qplot(speed, dist, data = cars) + geom_smooth()

## Error: konnte Funktion "qplot" nicht finden

How

• source editor: RStudio (perfect integration with knitr; one-click compilation); currently you have to use the preview version (>= 0.96.109)
• HTML5 slides converter: pandoc; this document was generated by: pandoc -s -S -i -t dzslides --mathjax knitr-slides.md -o knitr-slides.html
• the file knitr-slides.md is the markdown output from its source: library(knitr); knitr('knitr-slides.Rmd')
• or simple click the button Knit HTML in RStudio

For ninjas

• you should tweak the default style; why not try some Google web fonts? (think how painful it is to wrestle with fonts in LaTeX)
• pandoc provides 3 types of HTML5 slides (dzslides is one of them)
• you can tweak the default template to get better appearances
• if you have come up with a better dzslides template, please let me know or contribute to pandoc directly (e.g. pre blocks should have max-width and max-height)

For beamer lovers

• pandoc supports conversion to beamer as well. period.

For Powerpoint lovers

• …

Reproducible research

It is good to include the session info, e.g. this document is produced with knitr version 0.5. Here is my session info:

print(sessionInfo(), locale = FALSE)

## R version 2.15.0 (2012-03-30)
## Platform: i386-pc-mingw32/i386 (32-bit)
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] knitr_0.5
## 
## loaded via a namespace (and not attached):
##  [1] codetools_0.2-8 digest_0.5.2    evaluate_0.4.2  formatR_0.4    
##  [5] highlight_0.3.1 parser_0.0-14   plyr_1.7.1      Rcpp_0.9.10    
##  [9] stringr_0.6     tools_2.15.0   

test knitr with md

myrand <- rnorm(1000)
print(myrand)

##    [1]  0.298648  0.097807  1.098522 -0.980199  0.414083 -0.890334
##    [7] -1.810151 -0.927236  0.976419 -0.938375  0.944158  0.136689
##   [13] -0.496647  1.972068  0.131926  0.890329  1.043478  0.260823
##   [19] -0.377063 -2.154834 -1.036861 -0.449526  0.190250 -0.400649
##   [25] -0.401424  0.053375 -0.705341  0.397825  0.800751 -0.140463
##   [31]  2.273931 -0.813813 -2.123324 -0.834271 -1.882028  0.172412
##   [37] -1.522355 -0.412939 -0.367475 -0.143851  0.812378  0.300966
##   [43]  0.259923  0.464625  0.251548  1.016711 -0.767624  0.055124
##   [49] -0.414004 -0.489951  0.046721 -0.838645  0.659773 -0.730307
##   [55] -2.582216 -0.253396 -0.565184 -0.970252 -1.173069  0.544127
##   [61] -1.794837  0.632779  0.567508  0.615080  0.143358 -1.824048
##   [67]  1.780278  0.523726 -0.305446  0.270077  0.938519  1.316575
##   [73]  1.063443  0.175906  0.224533  0.824766  0.870568 -0.918986
##   [79] -0.913198 -0.541987  1.367404 -1.585056  0.713233  0.040854
##   [85] -0.372786 -1.382347 -0.731435 -0.644262  1.120517  0.885817
##   [91] -1.239299 -0.749014 -0.407541  0.835214  1.081835 -0.799044
##   [97]  1.099868 -0.044881  1.238784  1.255065 -0.349501 -1.263979
##  [103] -1.673888 -1.002229  0.019447 -0.628839  0.171294  0.426224
##  [109] -0.263587 -0.008085  0.461601 -0.890573 -0.017283 -1.101671
##  [115] -0.979672 -0.264693 -0.148817  0.882898 -1.080117 -0.426623
##  [121]  0.267392  0.681272 -1.285526  0.786348  0.042349 -0.547281
##  [127]  1.549434 -1.134289  1.118007 -0.670090  0.685195  0.356221
##  [133]  0.366527 -1.180710  0.005321  0.878337  0.920955 -1.325586
##  [139] -0.019480  2.116472 -0.115492 -0.158657  0.701671 -0.895577
##  [145] -0.086698  0.972655  0.916140  1.039462 -1.413916  0.799082
##  [151] -0.719161  1.384878  1.184943  1.700237  0.085097  1.275678
##  [157] -0.407128  0.119141 -0.368721  0.656854 -0.686423 -0.748832
##  [163]  0.608064  0.328718 -0.166386  1.481732  1.254580  1.626073
##  [169]  0.616276 -0.671803  0.213229 -2.086910  1.772728 -0.408240
##  [175] -0.993180  0.450090  1.865949  1.016262  1.255167 -0.411175
##  [181] -1.122495  1.772564 -0.159282 -0.957827 -1.526622 -1.146077
##  [187] -0.950203  0.601392  1.098072  2.028996  0.374907  0.309464
##  [193]  0.169294 -0.020930 -0.310341 -1.325303  1.903042  0.337052
##  [199]  0.446381  0.147781 -1.424223  1.313376 -0.788691 -0.930490
##  [205]  0.285293  1.670330  1.292715 -0.438629  0.637391 -1.297890
##  [211] -1.840273  1.253820 -0.708142  0.960765 -0.964583 -0.296722
##  [217]  1.927957 -0.161281 -0.916178  0.478323  1.377466  0.150846
##  [223]  1.018510  0.194269  0.310692  0.183750  0.409511  0.718055
##  [229] -0.183297 -0.873294  0.325410 -0.551486 -0.146156 -0.016792
##  [235] -0.756890  0.736873 -0.143695  0.655234  0.170264  1.132104
##  [241]  0.722659 -0.494549  0.267587  0.515649 -0.546520 -0.162699
##  [247] -0.356685  0.504735 -0.689094 -0.477180  1.669608 -0.994640
##  [253] -1.885902  0.338671 -1.036225  0.608006 -0.745126 -0.340526
##  [259] -0.110149 -0.056545 -1.531658 -0.629233  1.987259 -0.225564
##  [265]  1.166523  0.152208  0.929647  0.008929 -0.557223 -1.445771
##  [271] -0.707322 -0.744925  1.330392 -0.682180  0.532883  1.135439
##  [277]  0.997525  0.774507  0.471326  0.652426 -1.564335  1.609435
##  [283]  0.024425  1.009476 -0.530146  1.179785 -0.457991  0.171040
##  [289]  0.089695  1.618717 -1.474910  0.928011  0.590663 -1.288114
##  [295]  0.328050 -0.355698 -0.336423  0.490940  2.912575 -0.848093
##  [301] -0.198312 -1.037850 -0.700185  0.889277 -0.154991  1.569301
##  [307]  1.653238  1.576336 -1.587504  0.941530  0.721037 -0.719266
##  [313] -0.550308  0.539802 -0.171566 -0.748296 -1.085623 -0.920903
##  [319] -0.206273  1.420537 -1.004861 -0.009414 -0.039099  0.340261
##  [325]  0.094058 -1.028257  0.657049  1.252944  1.478115 -0.513833
##  [331] -0.142215  0.945185  0.057882  1.865921  0.220593  0.412724
##  [337] -1.917831  0.253279 -1.647194  0.727642 -0.092756  0.544097
##  [343]  1.593484  0.636706  1.991604  0.050331 -0.635108 -1.700082
##  [349] -0.332505 -0.361090 -0.076391 -0.853462 -0.932693 -0.073912
##  [355]  2.383984 -0.309274  1.280500 -1.010667  0.138323 -1.443499
##  [361] -0.087442 -0.160641 -0.758313  1.298206 -1.049202 -0.949688
##  [367]  0.181202 -0.271029  1.279136 -0.331893  0.783506  1.553871
##  [373]  0.308188  0.580696 -1.234289 -0.573738  1.009919 -0.954327
##  [379]  1.493018  0.880737 -1.803509 -0.517283 -0.822129  0.633162
##  [385]  0.233587 -0.140640  0.457887  0.421436  0.771851 -0.846056
##  [391]  0.113608 -0.192967  0.898215 -1.422951 -0.419319 -1.793665
##  [397]  1.747892 -1.206239 -1.370433  1.646605 -0.380896  1.103089
##  [403] -0.613350  1.661652  0.417948  1.340320 -2.211632 -0.613045
##  [409]  0.195599 -0.237959  0.286565 -0.175080 -0.080877 -1.382198
##  [415] -2.432714  0.054239 -0.384097 -1.359059  2.261578 -0.095714
##  [421]  1.234530  0.768527 -0.960789  0.502763 -0.285123  0.894852
##  [427]  0.227305  1.704501 -0.122158 -1.052541  0.176965  0.683217
##  [433]  0.304103 -0.459058  0.098587 -0.573309 -1.026686  0.260486
##  [439]  0.503087  0.860445  0.596537 -1.298133  2.046201 -0.229590
##  [445] -0.155709 -0.571065  0.989553 -0.506952  0.083755 -1.350292
##  [451] -0.011542 -0.049994 -0.411472  0.107993  0.663799 -0.148141
##  [457] -1.097382  0.641474 -0.415068  0.108394  0.681912  0.841792
##  [463] -0.826772 -0.752161  2.672167  0.527065  0.094738  0.803600
##  [469]  0.065954 -0.221955 -0.906707  0.182244  0.293780  0.924485
##  [475]  0.362343 -0.211849  0.333798  0.153409 -1.214087 -1.524808
##  [481] -1.110297  0.663105 -1.600006  0.697672  1.734350  1.485171
##  [487]  0.234966 -0.401473  1.173660  1.263602  0.524320 -0.455097
##  [493] -0.277722  0.401417  2.346780  0.764203  0.571060 -1.457903
##  [499]  0.335037  1.432701 -0.232669  0.730349 -1.070946 -0.504890
##  [505]  0.223373 -1.417948  1.184482 -0.163189  0.370250  0.849831
##  [511]  1.398262 -0.181490  0.485306 -0.210910  1.205478  0.084220
##  [517]  0.591280 -1.124085 -0.896735  0.702369  0.999984  0.100355
##  [523] -0.119991  1.277344  0.789164 -0.216540  1.647307  1.100290
##  [529]  0.352928  0.055950  0.865874  1.232394  0.435013 -0.986355
##  [535] -0.128407 -1.062617 -0.963489  0.790424  2.035095  0.439261
##  [541] -1.171049 -0.473163 -1.760765 -1.190292  0.139972  2.044365
##  [547] -0.488700  1.278649  2.147338 -2.197461 -0.073299  0.179039
##  [553] -0.290609  0.948875 -0.602696 -0.194392 -0.894583 -0.046310
##  [559]  1.437286 -0.085701  0.370430  0.452034  0.385711  0.518531
##  [565] -1.483252  0.861664  1.213187  2.151369 -0.514469  0.891686
##  [571]  1.116925  0.395959 -0.263834  1.681755  1.290441  1.626740
##  [577] -0.844671  0.293022  0.485611  0.073937 -0.811694  0.004390
##  [583] -0.839440 -0.980162 -0.503946  0.291804  0.923471  0.174204
##  [589]  0.133357 -0.493278 -0.501599  0.048443  0.035368  0.726139
##  [595] -1.092485 -0.201379 -1.057956 -0.094797  0.305221 -1.697926
##  [601]  0.398701  1.046455 -1.329740 -0.410585 -0.185443 -0.242652
##  [607] -0.063018 -1.714042 -0.647946 -0.654954 -0.185083 -1.084822
##  [613]  0.349178  1.079327  1.670463  0.456502  0.693863  0.628991
##  [619] -1.423313 -0.399644  0.394306  0.763459 -0.646767  0.170940
##  [625]  0.039939  1.226702 -1.629326  0.132171 -0.293236 -1.299933
##  [631] -0.168130 -0.799420 -0.948028  0.552616  0.283296  0.611831
##  [637]  2.318136  0.884551  0.066446  0.430620 -0.512263  1.768707
##  [643] -0.607940  2.301534  0.246709 -0.498862  0.527477 -0.288065
##  [649] -2.051930 -0.858936 -0.137615 -0.558217 -0.582442 -1.224142
##  [655] -0.314688 -0.843618  0.607683 -0.776282 -0.402508  2.124496
##  [661] -0.568737  0.210659 -0.074997  0.711144 -0.184539  0.199631
##  [667]  2.488796 -0.826634 -2.260062  1.361870 -0.042833  0.425819
##  [673] -1.572065  1.224222 -0.145094  0.338514  0.378459  1.601348
##  [679] -1.375190  0.007862 -0.380316  1.136382 -0.309661 -0.416657
##  [685] -1.445045  0.089669 -0.150881 -0.639774  1.460012  0.896124
##  [691] -0.545451 -0.140666 -0.189935 -0.888564  2.012820  0.324735
##  [697] -0.286734  1.598820 -0.826403 -1.682724  1.504550 -1.207007
##  [703]  0.457392 -0.768796 -0.448603  1.511268  0.472090 -0.130907
##  [709] -0.108796 -0.322552 -0.021521 -1.785784  0.552739 -0.671138
##  [715] -0.454815  0.810335  1.327782 -1.084482 -0.826414  0.670599
##  [721]  0.790540 -0.443951  0.034382 -0.464909  1.262628 -0.158256
##  [727]  0.560834  0.039702  1.439423 -0.999893  0.491948 -0.183882
##  [733]  0.955411 -0.087583 -0.450185 -1.430371 -0.820052  0.412846
##  [739]  0.849826 -0.192245  2.150402 -0.521264  0.277654 -0.884207
##  [745] -0.317057 -1.139917 -1.700484 -0.356621 -0.886443  0.371727
##  [751] -0.487070  0.702466  0.910585 -1.483797 -0.820153  0.833100
##  [757]  0.512290  0.156223 -1.169403 -0.173944  1.246705  0.319651
##  [763]  0.686033 -1.133747  0.842454  1.460656  0.490008  0.809458
##  [769] -0.302997 -2.443605  0.480094  0.467579  0.522098  0.316467
##  [775] -1.732099 -1.240356  0.800987 -0.205253  2.515637  1.216495
##  [781]  0.267253 -0.966055  0.144501  1.082905 -0.599473  0.903458
##  [787]  1.546076 -0.944869  0.935744  1.401405 -0.394098 -1.029259
##  [793]  0.378667  0.044982 -0.886794  0.707499  0.797668  1.016456
##  [799] -0.380790 -0.004963  0.917324  0.254980  0.030507  0.587396
##  [805] -1.017613 -0.611682  1.575041 -0.374501 -0.854477 -1.194674
##  [811] -0.331463 -0.473947  0.680730 -0.169899 -1.191445  0.813222
##  [817] -1.696054  1.073172 -1.168461  0.702445 -1.219489 -0.730749
##  [823]  0.010005  0.889402  0.765168 -0.480976 -0.795306 -0.915192
##  [829]  0.403714  1.139489  1.012424 -0.180238 -0.899779 -1.096393
##  [835]  0.301074  1.325230  1.104553  0.090727  0.828426 -1.092934
##  [841]  2.198077  0.334660  0.813179 -0.661544  1.088221  0.450266
##  [847] -1.178059 -0.456715 -1.027932 -1.228852  0.019116 -0.110031
##  [853] -0.302875  1.324966 -1.192865  0.690128  1.501410 -1.551319
##  [859]  1.816845  1.145083 -0.166400  1.318758  0.103203  0.169205
##  [865]  1.416332  1.597047 -0.469196 -0.589926 -0.499735 -2.123869
##  [871] -0.195118 -0.850422  1.114903  0.749405  1.353753  0.747084
##  [877]  0.750452 -0.388172 -0.249030  0.671154  0.654909  0.794977
##  [883]  0.680633 -0.254817 -1.240083  0.033299 -1.337107  1.681244
##  [889] -0.752860  0.351564 -0.776012  1.258390  1.774746 -0.017863
##  [895] -0.753153 -1.330503  0.350446  0.095405  1.588947  1.393986
##  [901] -0.344217 -0.831855  0.611995  1.218971 -0.144198 -1.256839
##  [907]  1.112980  0.300175 -0.646624  0.371647  1.592677 -1.167624
##  [913] -1.451210 -0.323991  0.040031 -0.123726  0.765885  1.121448
##  [919]  0.097962  0.458236 -0.603580  1.037632  0.198658 -0.538048
##  [925] -0.327835  0.273892 -0.578336  0.823098 -0.402788  0.171321
##  [931] -0.549798  0.755466  0.021636  0.377165  0.819272 -0.274990
##  [937] -0.690997  0.531066 -0.312396 -0.436401 -0.431764  1.799187
##  [943]  0.480449 -0.324250  1.217805 -2.132254  0.300075  0.902926
##  [949] -1.047265 -0.914479 -0.661227  0.845175 -1.808106  0.838016
##  [955] -0.688608  0.495622  0.485172 -1.160202 -1.211468  0.773292
##  [961]  1.244937  0.533809 -0.900026 -2.045845  0.751081 -0.497309
##  [967] -1.136760 -1.358087 -1.346666 -0.471949 -0.735591  0.022593
##  [973] -0.845751  1.866582 -1.515521 -1.990738 -0.889704 -0.175608
##  [979]  0.312449 -0.498655 -0.332243  0.308052 -1.016647 -1.155445
##  [985]  0.432879 -0.304469 -0.457805 -0.270676  0.271141  2.141514
##  [991] -0.503733  0.995394  0.862173  0.236618  0.126809 -0.155623
##  [997]  0.941450 -0.726356 -0.398826  1.043359

Life is short

• so keep your audience awake!