MonkmanMH / gist:4970480

Created February 17, 2013


    
    View gist:4970480 
  
  
      gistfile1.r
    
    
        Raw
      
    
    File suppressed. Click to show.
  
  
            1
            2
            3
            4
            5
            6
            7
            8
            9
            10
            11
            12
            13
            14
            15
            16
            17
            18
            19
            20
            21
            22
            23
            24
            25
            26
            27
            28
            29
            30
            31
            32
            33
            34
            35
            36
            37
            38
            39
            40
            41
            42
            43
            44
            45
            46
            47
            48
            49
            50
            51
            52
            53
            54
            55
            56
            57
            58
            59
            60
            61
            62
            63
            64
            65
            66
            67
            68
            69
            70
            71
            72
            73
            74
            75
            76
            77
            78
            79
            80
            81
            82
            83
            84
            85
            86
            87
            88
            89
            90
            91
            92
            93
            94
            95
            96
            97
            98
            99
            100
            101
            102
            103
            104
            105
            106
            107
            108
            109
            110
            111
            112
            113
            114
            115
            116
            117
            118
            119
            120
            121
            122
            123
            124
            125
            126
            127
            128
            129
            130
            131
            132
            133
            134
            135
            136
            137
            138
            139
            140
            141
            142
            143
            144
            145
            146
            147
            148
            149
            150
            151
            152
            153
            154
            155
            156
            157
            158
            159
            160
            161
            162
            163
            164
            165
            166
            167
            168
            169
            170
            171
            172
            173
            174
            175
            176
            177
            178
            179
            180
            181
            182
            183
            184
            185
            186
            187
            188
            189
            190
            191
            192
            193
            194
            195
            196
            197
            198
            199
            200
            201
            202
            203
            204
            205
            206
            207
            208
            209
            210
            211
            212
            213
            214
            215
            216
            217
            218
            219
            220
            221
            222
            223
            224
            225
            226
            227
            228
            229
            230
            231
            232
            233
            234
            235
            236
            237
            238
            239
            240
            241
            242
            243
            244
            245
            246
            247
            248
            249
            250
            251
            252
            253
            254
            255
            256
            257
            258
            259
            260
            261
            262
            263
            264
            265
            266
            267
            268
            269
            270
            271
            272
            273
            274
            275
            276
            277
            278
            279
            280
            281
            282
            283
          
          
            # MAJOR LEAGUE BASEBALL - RUNS PER GAME TREND
#
# discussion at 
# 1.  http://bayesball.blogspot.ca/2012/07/trends-in-al-run-scoring-using-r.html
# 2.  http://bayesball.blogspot.ca/2012/07/trends-in-run-scoring-nl-edition-more-r.html
# 3.  http://bayesball.blogspot.ca/2012/08/trends-in-run-scoring-comparing-leagues.html
#
# data source: Baseball Reference
# http://www.baseball-reference.com
# http://www.baseball-reference.com/leagues/AL/bat.shtml
# http://www.baseball-reference.com/leagues/NL/bat.shtml
#
# open with "csv" option (top right corner of the table), 
# copy and paste into text editor or Excel, save as CSV file
#
# set working directory
# setwd("K:/data/R_the software/datatrials/baseball/RunsPerGame")
# read the data into a table
ALseason <- read.table(file="ALseasons.csv", sep = ",", header = TRUE)
NLseason <- read.table(file="NLseasons.csv", sep = ",", header = TRUE)
#
# alternate approach to reading NL season, from .txt file
NLseason <- read.table(file="NLseasons.txt", sep = ",", header = TRUE)
#
#
# RUNS SCORED PER GAME
# ====================
#
# start with American League
#
# very simple plot -- as (x, y)
plot(ALseason$Year, ALseason$R)
# as (y predicted by x)
plot(ALseason$R ~ ALseason$Year)
#
# create new object ALRunScore.LO for loess model
ALRunScore.LO <- loess(ALseason$R ~ ALseason$Year)  			
ALRunScore.LO.predict <- predict(ALRunScore.LO)
#
# plot the data, add loess curve
ylim <- c(3,6)
plot(ALseason$R ~ ALseason$Year, 
  ylim = ylim, 
  main = "American League: runs per team per game, 1901-2012", 
  xlab = "year", ylab = "runs per game")
# chart tidying
  grid()
# loess predicted value line
  lines(ALseason$Year, ALRunScore.LO.predict, 
    lty="solid", col="red", lwd=2)	
#
#
# VERSION 2 -- add "span" control to adjust smoothing
#
# references: 
#  http://princeofslides.blogspot.ca/2011/05/sab-r-metrics-basics-of-loess.html 
#  http://research.stowers-institute.org/efg/R/Statistics/loess.htm
#
# create new object RunScore.LO for loess model, span=0.25
ALRunScore.LO.25 <- loess(ALseason$R ~ ALseason$Year, span=0.25)				
ALRunScore.LO.25.predict <- predict(ALRunScore.LO.25)
#
ALRunScore.LO.5 <- loess(ALseason$R ~ ALseason$Year, span=0.5)				
ALRunScore.LO.5.predict <- predict(ALRunScore.LO.5)
#
# plot the data, add loess curve
ylim <- c(3,6)
plot(ALseason$R ~ ALseason$Year, 
  ylim = ylim, 
  main = "American League: runs per team per game, 1901-2012", 
  xlab = "year", ylab = "runs per game")
# loess predicted value line
  lines(ALseason$Year, ALRunScore.LO.predict, lty="solid", col="red", lwd=2)
  lines(ALseason$Year, ALRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2)
  lines(ALseason$Year, ALRunScore.LO.5.predict, lty="dotdash", col="black", lwd=2)
# chart tidying
  legend(1980, 3.5, 
    c("default", "span=0.25", "span=0.50"), 
    lty=c("solid", "dashed", "dotdash"), 
    col=c("red", "blue", "black"), 
    lwd=c(2, 2, 2))
  grid()
#
#
#
#-N-N-N-N-N-N-N-N-N-N-N-N-N-N
#
# NATIONAL LEAGUE
#
# create new object RunScore.LO for loess model
NLRunScore.LO <- loess(NLseason$R ~ NLseason$Year)				
NLRunScore.LO.predict <- predict(NLRunScore.LO)
#
# plot the data, add loess curve
ylim <- c(3,6)
plot(NLseason$R ~ NLseason$Year, 
  pch=2, col="black",
  ylim = ylim, 
  main = "National League: runs per team per game, 1901-2012", 
  xlab = "year", ylab = "runs per game")
# loess predicted value line
  lines(NLseason$Year, NLRunScore.LO.predict, lty="solid", col="blue", lwd=2)	
# chart tidying
  grid()
#
#
# VERSION 2 -- add "span" control to adjust smoothing
#
# reference: http://research.stowers-institute.org/efg/R/Statistics/loess.htm
#
# create new object RunScore.LO for loess model
NLRunScore.LO.25 <- loess(NLseason$R ~ NLseason$Year, span=0.25)				
NLRunScore.LO.25.predict <- predict(NLRunScore.LO.25)
NLRunScore.LO.5 <- loess(NLseason$R ~ NLseason$Year, span=0.5)				
NLRunScore.LO.5.predict <- predict(NLRunScore.LO.5)
#
# plot the data, add loess curve
ylim <- c(3,6)
plot(NLseason$R ~ NLseason$Year, 
  pch=2, col="black",
  ylim = ylim, 
  main = "National League: runs per team per game, 1901-2012", 
  xlab = "year", ylab = "runs per game")
# loess predicted value line
  lines(NLseason$Year, NLRunScore.LO.predict, lty="solid", col="blue", lwd=2)
  lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="red", lwd=2)
  lines(NLseason$Year, NLRunScore.LO.5.predict, lty="dotdash", col="black", lwd=2)
# chart tidying
  legend(1980, 3.5, 
    c("default", "span=0.25", "span=0.50"), 
    lty=c("solid", "dashed", "dotdash"), 
    col=c("blue", "red", "black"), 
    lwd=c(2, 2, 2))
  grid()
#
#
#
#
# MULTI-PLOT -- MERGING AL AND NL RESULTS
#
# plot individual years as points
ylim <- c(3,6)
# start with AL
plot(ALseason$R ~ ALseason$Year,
  type="p", pch=1, col="black",
  main = "Runs per team per game, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add NL line
  points(NLseason$Year, NLseason$R, pch=2, col="blue")
# chart additions
  grid()
  legend(1900, 6, c("AL", "NL"), pch=c(1, 2), col=c("black", "blue"))
#
 
# plot individual years as lines
ylim <- c(3,6)
# start with AL line
plot(ALseason$R ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=2,
  main = "Runs per team per game, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add NL line
  lines(NLseason$Year, NLseason$R, lty="solid", col="blue", lwd=2)
# chart additions
  grid()
  legend(1900, 3.5, c("AL", "NL"), lty=c("solid", "solid"), col=c("red", "blue"), lwd=c(2, 2))
#
#
# plot loess curves (span=0.25)
ylim <- c(3,6)
# start with AL line
plot(ALRunScore.LO.25.predict ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=2,
  main = "Runs per team per game, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add NL line
  lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2)
# chart additions
   legend(1900, 3.5, 
    c("AL (span=0.25)", "NL (span=0.25)"), 
    lty=c("solid", "dashed"), 
    col=c("red", "blue"), 
    lwd=c(2, 2))
  grid()
#
#
# plot loess curves (span=0.50)
ylim <- c(3,6)
# start with AL line
plot(ALRunScore.LO.5.predict ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=2,
  main = "Runs per team per game, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add NL line
  lines(NLseason$Year, NLRunScore.LO.5.predict, lty="dashed", col="blue", lwd=2)
# chart additions
   legend(1900, 3.5, 
    c("AL (span=0.50)", "NL (span=0.50)"), 
    lty=c("solid", "dashed"), 
    col=c("red", "blue"), 
    lwd=c(2, 2))
  grid()
#
#
#
# plot multiple loess curves (span=0.50 and 0.25)
ylim <- c(3,6)
# start with AL line
plot(ALRunScore.LO.5.predict ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=2,
  main = "Runs per team per game, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add NL line
  lines(NLseason$Year, NLRunScore.LO.5.predict, lty="solid", col="blue", lwd=2)
# add 0.25 lines
  lines(ALseason$Year, ALRunScore.LO.25.predict, lty="dashed", col="red", lwd=2)
  lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2)
# chart additions
   legend(1900, 3.5, 
    c("AL (span=0.50)", "NL (span=0.50)", "AL (span=0.25)", "NL (span=0.25)"), 
    lty=c("solid", "solid", "dashed", "dashed"), 
    col=c("red", "blue", "red", "blue"), 
    lwd=c(2, 2, 2, 2))
  grid()
#
# # # # # # # # # # # # # # # # # #
#
# calculate the difference between the two leagues 
# 1. absolute
RunDiff <- (ALseason$R - NLseason$R)
# 2. LOESS span=0.25
RunDiffLO <- (ALRunScore.LO.25.predict - NLRunScore.LO.25.predict)
#
# plot the LOESS difference
ylim <- c(-1,1)
plot(RunDiffLO ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=2,
  main = "Run scoring trend: AL difference from NL, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add line at zero
  abline(h = 0, lty="dotdash") 
  grid()
#
# plot each year difference as line, trend as line
ylim <- c(-1,1.5)
plot(RunDiffLO ~ ALseason$Year,
  type="l", lty="solid", col="red", lwd=3,
  main = "Run scoring trend: AL difference from NL, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add RunDiff line
  lines(ALseason$Year, RunDiff, lty="solid", col="black", lwd=1)
# add line at zero
  abline(h = 0, lty="dotdash") 
  grid()
#
#
# plot each year difference as bar, trend as line
ylim <- c(-1,1.5)
plot(RunDiff ~ ALseason$Year,
  type="h", lty="solid", col="blue", lwd=2,
  main = "Run scoring trend: AL difference from NL, 1901-2012", 
  ylim = ylim, 
  xlab = "year", ylab = "runs per game")
# add RunDiff line
  lines(ALseason$Year, RunDiffLO, lty="solid", col="black", lwd=2)
# add line at zero
  abline(h = 0, lty="dotdash") 
# chart additions
  grid()
  legend(1900, 1.5, 
    c("AL difference from NL: absolute", "AL difference from NL, LOESS (span=0.25)"), 
    lty=c("solid", "solid"), 
    col=c("blue", "black"), 
    lwd=c(2, 2))
#
#