I'm new to R, so forgive my ignorance. I'm playing around with a dataset that reflects the mileage my car has achieved since I got it. Here's the data formatted .csv. (Note: I have this data in excel and when I saved it as .txt space delimited there was an issue where one line kept throwing an error on read.table saying there weren't the right number of columns...so I switched to .csv and it worked fine)
Date,Miles,Gallons,Price.per.Gallon,Total.Cost,Grade,MPG,Price.per.Mile,Cumulative.Miles,Cumulative.Gallons,Cumulative.Cost,Cumulative.MPG,Cumulative.Price.per.Mile,Gas.Source,Car.Said,Delta,Average.Price.of.Gas,Avg.Temp
6/8/2011,391.8,9.751,3.749,36.556499,Regular,40.18049431,0.093303979,570.4,9.751,36.56,40.18049431,0.064095372,Dealer,41.18,1,3.74935904,82.8
6/22/2011,441.2,9.566,3.359,32.132194,Regular,46.12168095,0.072829089,1011.6,19.317,68.692194,43.14334524,0.067904502,Speedway,47,0.878319047,3.556048765,73.2
7/7/2011,460.6,9.594,3.599,34.528806,Regular,48.0091724,0.074964842,1472.2,28.911,103.221,44.75805057,0.070113436,BP,49.4,1.390827601,3.570301961,79.5
7/18/2011,397.4,8.178,3.319,27.142782,Regular,48.59378821,0.068300911,1869.6,37.089,130.363782,45.60381784,0.069728168,Shell,45.7,2.893788212,3.514890722,83.1
7/26/2011,368.7,8.959,3.359,30.093281,Regular,41.15414667,0.081619965,2238.3,46.048,160.457063,44.73809937,0.071687023,Kroger,42.9,1.745853332,3.484560958,79.1
8/8/2011,436.3,9.845,3.559,35.038355,Regular,44.31691214,0.080307942,2674.6,55.893,195.495418,44.6639114,0.073093329,Kroger,48,3.683087862,3.49767266,76
8/9/2011,262.2,4.986,3.479,17.346294,Regular,52.58724428,0.066156728,2936.8,60.879,212.841712,45.31283365,0.072474023,Shell,46.9,5.687244284,3.496143366,74.5
8/13/2011,250.1,5.887,3.369,19.833303,Regular,42.48343808,0.079301491,3186.9,66.766,232.675015,45.0633556,0.073009826,mobil,45.5,3.016561916,3.484932675,74.1
8/14/2011,424.4,8.699,3.759,32.699541,Regular,48.78721692,0.077048871,3611.3,75.465,265.374556,45.49261247,0.073484495,Speedway,49,0.212783079,3.516524959,68
8/18/2011,437,9.594,3.399,32.610006,regular,45.54930165,0.074622439,4048.3,85.059,297.984562,45.49900657,0.073607332,Speedway,47.6,2.050698353,3.503269049,77.1
8/30/2011,407.3,9.244,3.429,31.697676,Regular,44.06101255,0.077823904,4455.6,94.303,329.682238,45.35804799,0.073992782,Shell,48.6,4.538987451,3.495988866,66.6
9/10/2011,347.3,7.992,3.549,28.363608,Regular,43.45595596,0.081668897,4802.9,102.295,358.045846,45.20944328,0.074547845,Meijer,49.6,6.144044044,3.500130466,65
9/21/2011,375,8.874,3.369,29.896506,Regular,42.25828262,0.079724016,5177.9,111.169,387.942352,44.97386861,0.07492272,Meijer,44.9,2.641717377,3.489663054,67.5
10/5/2011,404.8,9.243,3.079,28.459197,Regular,43.79530455,0.07030434,5582.7,120.412,416.401549,44.88340033,0.074587843,UDF,45.4,1.604695445,3.458139961,61.5
10/14/2011,376.5,8.715,3.249,28.315035,Regular,43.20137694,0.075205936,5959.2,129.127,444.716584,44.76987772,0.074626894,UDF,46.4,3.198623064,3.444024751,56.4
10/23/2011,382.8,8.953,3.199,28.640647,Regular,42.75661789,0.074818827,6342,138.08,473.357231,44.63933951,0.074638479,Speedway,43.8,1.043382107,3.428137536,50.3
10/31/2011,403.4,9.517,3.299,31.396583,Regular,42.38730692,0.077829903,6745.4,147.597,504.753814,44.49412928,0.074829338,Kroger,45.7,3.312693076,3.419810796,47.5
11/15/2011,402.8,9.146,3.249,29.715354,Regular,44.04111087,0.073771981,7148.2,156.743,534.469168,44.46769553,0.074769756,UDF,45.1,1.058889132,3.409843936,54.4
11/29/2011,361.1,9.209,3.149,28.999141,Regular,39.21164079,0.080307785,7509.3,165.952,563.468309,44.1760268,0.075036063,BP,41.7,2.488359214,3.395369197,42.8
12/10/2011,354.2,9.23,3.199,29.52677,Regular,38.37486457,0.083361858,7863.5,175.182,592.995079,43.87037481,0.075411087,Shell,40.3,1.925135428,3.385022885,22.8
12/19/2011,357.4,8.957,2.999,26.862043,Regular,39.90175282,0.075159605,8220.9,184.139,619.857122,43.67733071,0.075400154,UDF,41.3,1.398247181,3.366245727,41.8
1/5/2012,322.6,8.549,3.459,29.570991,Regular,37.73540765,0.091664572,8543.5,192.688,649.428113,43.41370506,0.076014293,Speedway,41,3.26459235,3.370360962,32.3
1/14/2012,370,9.148,3.319,30.362212,Regular,40.44599913,0.082060032,8913.5,201.836,679.790325,43.27919697,0.076265252,Shell,42,1.554000875,3.368033081,17.9
1/28/2012,327.3,9.108,3.329,30.320532,Regular,35.93544137,0.09263835,9240.8,210.944,710.110857,42.96211317,0.076845171,BP,37.5,1.56455863,3.366347737,32.1
2/9/2012,307,7.971,3.399,27.093429,Regular,38.51461548,0.088252212,9547.8,218.915,737.204286,42.80017358,0.077211953,Shell,41.1,2.585384519,3.367536651,28.8
2/16/2012,370.5,10.057,3.229,32.474053,Regular,36.84001193,0.087649266,9918.3,228.972,769.678339,42.53838897,0.077601841,Speedway,42.2,5.359988068,3.361451789,44
2/29/2012,406.3,9.518,3.759,35.778162,Regular,42.6875394,0.088058484,10324.6,238.49,805.456501,42.54434148,0.078013337,Shell,42.9,0.212460601,3.377317711,54.1
3/14/2012,370.6,9.812,3.699,36.294588,Regular,37.77007746,0.097934668,10695.2,248.302,841.751089,42.35567978,0.078703632,UDF,40.5,2.729922544,3.390029436,63.6
3/23/2012,357.6,7.999,3.929,31.428071,Regular,44.7055882,0.087886105,11052.8,256.301,873.17916,42.429019,0.07900072,Shell,43.1,1.605588199,3.406850383,66
4/3/2012,252.5,4.57,3.849,17.58993,Regular,55.25164114,0.069663089,11305.3,260.871,890.76909,42.65364874,0.078792167,Meijer,41.9,13.35164114,3.414596065,58.6
4/13/2012,382.3,9.416,3.629,34.170664,Regular,40.6011045,0.089381805,11687.6,270.287,924.939754,42.58214417,0.079138553,Shell,44.3,3.698895497,3.422065264,51.2
4/24/2012,393.7,9.018,3.659,32.996862,Regular,43.65713018,0.083812197,12081.3,279.305,957.936616,42.61685254,0.079290856,UDF,43.3,0.357130184,3.429715243,49.2
5/7/2012,354.7,9.203,3.729,34.317987,Regular,38.54177985,0.096752148,12436,288.508,992.254603,42.48686345,0.079788887,Speedway,40.6,2.058220146,3.439262007,70.3
5/18/2012,378,9.505,3.699,35.158995,Regular,39.76854287,0.093013214,12814,298.013,1027.413598,42.40016375,0.080178992,Speedway,42.2,2.431457128,3.447546241,62.2
6/1/2012,381.5,9.781,3.699,36.179919,Regular,39.0041918,0.094835961,13195.5,307.794,1063.593517,42.29224741,0.080602745,Sunoco,41,1.9958082,3.455536875,61.4
6/12/2012,386.8,8.976,3.649,32.753424,Regular,43.09269162,0.084677932,13582.3,316.77,1096.346941,42.31492881,0.080718799,Meijer,44.1,1.007308378,3.46101885,75.5
6/23/2012,379.9,9.168,3.339,30.611952,Regular,41.43760908,0.080578973,13962.2,325.938,1126.958893,42.29025152,0.080714994,Kroger,41.8,0.362390925,3.457586697,74.4
7/8/2012,321.9,8.285,3.549,29.403465,Regular,38.85334943,0.091343476,14284.1,334.223,1156.362358,42.20505471,0.080954513,Shell,40.9,2.046650573,3.459852727,84.1
7/21/2012,369.5,8.88,3.479,30.89352,Regular,41.61036036,0.083608985,14653.6,343.103,1187.255878,42.18966316,0.081021447,Meijer,42.6,0.98963964,3.460348286,70.1
7/21/2012,385,7.808,3.499,27.320192,Regular,49.30840164,0.070961538,15038.6,350.911,1214.57607,42.34805976,0.080763906,Speedway,48.5,0.808401639,3.461208312,70.1
7/26/2012,367.1,9.644,3.479,33.551476,Regular,38.06511821,0.091396012,15405.7,360.555,1248.127546,42.23350113,0.081017256,BP,44.2,6.134881792,3.461684198,82.5
8/12/2012,376.6,9.287,3.769,35.002703,Regular,40.55130828,0.09294398,15782.3,369.842,1283.130249,42.19126005,0.081301854,BP,42.3,1.74869172,3.46940112,66.4
8/24/2012,414.9,9.22,3.859,35.57998,Regular,45,0.085755556,16197.2,379.062,1318.710229,42.25957759,0.081415938,Speedway,44.6,0.4,3.478877411,76.5
9/9/2012,373.3,8.984,3.799,34.130216,Regular,41.55164737,0.091428385,16570.5,388.046,1352.840445,42.24318766,0.081641498,Speedway,42.8,1.248352627,3.486288855,62.1
9/19/2012,408.1,9.123,3.799,34.658277,Regular,44.73309218,0.084925942,16978.6,397.169,1387.498722,42.30038095,0.081720443,BP,46.5,1.766907815,3.493471852,53.5
9/28/2012,408.3,9.281,3.659,33.959179,Regular,43.99310419,0.083172126,17386.9,406.45,1421.457901,42.33903309,0.081754534,BP,45.6,1.606895809,3.497251571,59
10/7/2012,393.1,8.942,3.699,33.076458,Regular,43.96108253,0.084142605,17780,415.392,1454.534359,42.37395039,0.081807332,Speedway,46.3,2.338917468,3.50159454,45
10/15/2012,402.9,9.075,3.549,32.207175,Regular,44.39669421,0.079938384,18182.9,424.467,1486.741534,42.41719615,0.081765919,Speedway,46.1,1.703305785,3.502608057,54.6
10/24/2012,365.7,8.264,3.299,27.262936,Regular,44.25217812,0.074550003,18548.6,432.731,1514.00447,42.45223938,0.081623652,Speedway,46.8,2.547821878,3.49871969,68.5
11/4/2012,363.3,9.561,3.259,31.159299,Regular,37.99811735,0.085767407,18911.9,442.292,1545.163769,42.35595489,0.081703254,Meijer,42,4.001882648,3.493537683,37.3
11/15/2012,391.9,10.224,3.499,35.773776,Regular,38.33137715,0.091282919,19303.8,452.516,1580.937545,42.26502488,0.081897737,Speedway,44.1,5.768622848,3.493661097,33.7
11/24/2012,430.2,9.068,3.579,32.454372,Regular,47.44155271,0.075440195,19734,461.584,1613.391917,42.36671982,0.081756963,BP,44.3,3.141552713,3.495337614,29.5
12/2/2012,394.5,9.146,3.239,29.623894,Regular,43.13361032,0.075092253,20128.5,470.73,1643.015811,42.38162004,0.081626341,Sunoco,45.8,2.666389679,3.490357128,55.1
12/12/2012,386.1,9.312,3.169,29.509728,Regular,41.46262887,0.076430272,20514.6,480.042,1672.525539,42.36379317,0.081528547,Speedway,43.4,1.937371134,3.484123345,31
12/23/2012,359.8,8.642,3.199,27.645758,Regular,41.63388105,0.076836459,20874.4,488.684,1700.171297,42.35088523,0.081447673,Speedway,42.4,0.766118954,3.479081159,30.7
1/6/2013,336.4,8.878,3.079,27.335362,Regular,37.89141699,0.081258508,21210.8,497.562,1727.506659,42.27131493,0.081444672,Meijer,41,3.108583014,3.47194251,33.2
1/21/2013,350,9.257,3.259,30.168563,Regular,37.80922545,0.086195894,21560.8,506.819,1757.675222,42.1898153,0.0815218,Meijer,40.6,2.790774549,3.468053135,20.8
2/1/2013,335.7,9.058,3.499,31.693942,Regular,37.0611614,0.094411504,21896.5,515.877,1789.369164,42.09976409,0.081719415,Meijer,38.7,1.638838596,3.468596514,12.1
2/13/2013,360.9,9.42,3.759,35.40978,Regular,38.31210191,0.098115212,22257.4,525.297,1824.778944,42.03184103,0.08198527,Speedway,41.4,3.087898089,3.473804236,31
2/26/2013,371.3,9.081,3.899,35.406819,Regular,40.88756745,0.09535906,22628.7,534.378,1860.185763,42.01239572,0.082204712,Meijer,42.2,1.312432551,3.481029838,36.9
3/9/2013,362.6,8.952,3.439,30.785928,Regular,40.5049151,0.084903276,22991.3,543.33,1890.971691,41.98755821,0.082247271,BP,42.7,2.195084897,3.480337347,36.5
3/21/2013,375.3,8.991,3.859,34.696269,Regular,41.74174174,0.092449424,23366.6,552.321,1925.66796,41.98355666,0.082411132,Kroger,44,2.258258258,3.486501437,23.8
4/8/2013,361.7,9,3.299,29.691,Regular,40.18888889,0.082087365,23728.3,561.321,1955.35896,41.95478167,0.082406197,Speedway,43.4,3.211111111,3.483495112,61.8
4/20/2013,362.3,8.036,3.699,29.725164,Regular,45.08461921,0.082045719,24090.6,569.357,1985.084124,41.99895672,0.082400776,BP,45.6,0.515380786,3.486536784,39
4/30/2013,382.3,8.246,3.539,29.182594,Regular,46.36187242,0.076334277,24472.9,577.603,2014.266718,42.06124276,0.082306009,Speedway,48.7,2.338127577,3.487285762,60.2
5/9/2013,397.3,8.722,3.339,29.122758,Regular,45.55147902,0.073301681,24870.2,586.325,2043.389476,42.1131625,0.082162165,Pilot,47.4,1.848520981,3.485079906,65.8
5/18/2013,399,9.051,3.899,35.289849,Regular,44.08352668,0.088445737,25269.2,595.376,2078.679325,42.14311628,0.082261382,Kroger,45.7,1.616473318,3.491372385,68.3
5/30/2013,380.2,9.04,3.659,33.07736,Regular,42.05752212,0.086999895,25649.4,604.416,2111.756685,42.14183609,0.082331621,Sunoco,44.4,2.342477876,3.493879522,78.2
6/14/2013,395.3,9.095,3.759,34.188105,Regular,43.46344145,0.086486479,26044.7,613.511,2145.94479,42.16142824,0.082394683,Meijer,45,1.536558549,3.497809803,67.6
6/22/2013,390.3,9.008,3.559,32.059472,Regular,43.32815275,0.082140589,26435,622.519,2178.004262,42.17831102,0.082390931,BP,44.3,0.971847247,3.49869524,78.2
7/4/2013,388.9,9.501,3.399,32.293899,Regular,40.93253342,0.083039082,26823.9,632.02,2210.298161,42.15958356,0.082400328,BP,43.7,2.767466582,3.497196546,71.6
7/18/2013,399.8,9.06,3.299,29.88894,Regular,44.12803532,0.07475973,27223.7,641.08,2240.187101,42.18740251,0.08228812,Speedway,45.2,1.07196468,3.494395553,83.9
8/25/2013,394.3,9.114,3.529,32.163306,Regular,43.2631117,0.081570647,27618,650.194,2272.350407,42.20248111,0.082277877,Kroger,45.8,2.536888304,3.494880616,74.6
9/5/2013,413.7,9.507,3.519,33.455133,Regular,43.51530451,0.0808681,28031.7,659.701,2305.80554,42.2214003,0.082257071,Speedway,46,2.484695488,3.495228202,70.2
9/14/2013,431.2,9.272,3.299,30.588328,Regular,46.50560828,0.070937681,28462.9,668.973,2336.393868,42.28077964,0.082085587,UDF,46.7,0.194391717,3.492508469,55.1
9/25/2013,417.6,9.685,3.159,30.594915,Regular,43.11822406,0.073263685,28880.5,678.658,2366.988783,42.29273065,0.081958026,Meijer,48.1,4.981775942,3.487749033,61.3
10/11/2013,421.9,9.202,3.299,30.357398,Regular,45.84872854,0.071954013,29302.4,687.86,2397.346181,42.34030181,0.081813987,Kroger,45.7,0.148728537,3.485224001,62.7
10/23/2013,389,8.975,3.259,29.249525,Regular,43.34261838,0.075191581,29691.4,696.835,2426.595706,42.35321131,0.081727224,Meijer,45.9,2.557381616,3.482310312,39.6
11/2/2013,392.8,8.852,3.299,29.202748,Regular,44.37415273,0.074345081,30084.2,705.687,2455.798454,42.3785616,0.081630838,Meijer,44.8,0.425847266,3.480010903,49.7
11/12/2013,363.5,9.114,2.959,26.968326,Regular,39.88369541,0.074190718,30447.7,714.801,2482.76678,42.34675105,0.081542014,Valero,44,4.116304586,3.473367804,31.4
11/24/2013,375.5,9.123,3.199,29.184477,Regular,41.15970624,0.077721643,30823.2,723.924,2511.951257,42.33179174,0.081495473,UDF,42.6,1.440293763,3.46991018,21.1
12/2/2013,364,9.006,2.999,27.008994,Regular,40.41749944,0.074200533,31187.2,732.93,2538.960251,42.30826955,0.08141033,Meijer,41.1,0.682500555,3.464123792,38.9
12/12/2013,325.8,8.576,2.979,25.547904,Regular,37.98973881,0.078415912,31513,741.506,2564.508155,42.25832293,0.081379372,Murphy,39.5,1.510261194,3.458513019,13.8
1/7/2014,317.1,8.915,3.199,28.519085,Regular,35.56926528,0.089937196,31830.1,750.421,2593.02724,42.17885693,0.081464628,Kroger,38.5,2.930734717,3.455430005,-3.6
1/15/2014,359.5,9.252,3.299,30.522348,Regular,38.85646347,0.08490222,32189.6,759.673,2623.549588,42.13839376,0.081503019,Meijer,41.1,2.243536533,3.453524856,28.6
1/27/2014,302.7,8.89,3.249,28.88361,Regular,34.04949381,0.095419921,32492.3,768.563,2652.433198,42.04482912,0.08163267,BP,35.8,1.750506187,3.451159109,37.1
2/4/2014,346.7,8.983,3.279,29.455257,Regular,38.59512412,0.084958918,32839,777.546,2681.888455,42.00497463,0.081667787,UDF,40,1.404875877,3.449170152,22.4
2/16/2014,310.1,8.773,3.459,30.345807,Regular,35.34708766,0.097858133,33149.1,786.319,2712.234262,41.93069225,0.081819243,Speedway,37.7,2.352912345,3.449279824,23.3
3/1/2014,361.8,9.065,3.599,32.624935,Regular,39.91174848,0.09017395,33510.9,795.384,2744.859197,41.90768233,0.081909444,Speedway,42.2,2.288251517,3.450986187,35.1
3/17/2014,354.2,9.356,3.579,33.485124,Regular,37.858059,0.094537335,33865.1,804.74,2778.344321,41.86060094,0.082041521,Speedway,41.9,4.041941,3.45247449,26.3
3/28/2014,354.1,9.165,3.579,32.801535,Regular,38.63611566,0.092633536,34219.2,813.905,2811.145856,41.82429153,0.082151127,UDF,39.8,1.163884343,3.453899234,51.9
4/8/2014,371.5,9.164,3.549,32.523036,Regular,40.53906591,0.087545184,34590.7,823.069,2843.668892,41.80998191,0.082209059,UDF,41.7,1.16093409,3.45495808,49.7
4/21/2014,373.8,9.216,3.679,33.905664,Regular,40.55989583,0.090705361,34964.5,832.285,2877.574556,41.79613954,0.082299891,Shell,42.2,1.640104167,3.457438925,64.1
5/2/2014,391.9,8.834,3.599,31.793566,Regular,44.36268961,0.081126731,35356.4,841.119,2909.368122,41.82309519,0.082286888,Speedway,44.8,0.437310392,3.458925695,50.9
5/10/2014,375.1,8.854,3.659,32.396786,Regular,42.36503275,0.086368398,35731.5,849.973,2941.764908,41.82874044,0.082329734,Speedway,45.8,3.434967246,3.46100983,65.5
5/21/2014,401.1,9.094,3.659,33.274946,Regular,44.10600396,0.082959227,36132.6,859.067,2975.039854,41.85284733,0.082336722,Speedway,45.6,1.493996041,3.463105734,72.3
6/6/2014,435.3,9.487,3.599,34.143713,Regular,45.88384105,0.0784372,36567.9,868.554,3009.183567,41.89687688,0.082290303,Speedway,50.5,4.616158954,3.464590074,67.5
6/21/2014,458.4,9.286,3.799,35.277514,Regular,49.36463493,0.076957928,37026.3,877.84,3044.461081,41.9758726,0.082224286,Kroger,49.6,0.235365066,3.468127541,73.8
7/5/2014,386.8,9.292,3.029,28.145468,Regular,41.6272062,0.072764912,37413.1,887.132,3072.606549,41.97222059,0.082126489,Speedway,44.5,2.872793801,3.463528031,69.2
7/19/2014,433.1,8.961,3.499,31.354539,Regular,48.33165941,0.072395611,37846.2,896.093,3103.961088,42.03581548,0.082015132,Kroger,48.3,0.031659413,3.463882753,66.7
8/6/2014,401.4,9.055,3.399,30.777945,Regular,44.32909994,0.076676495,38247.6,905.148,3134.739033,42.05875724,0.081959104,Speedway,47.6,3.270900055,3.463233673,73.1
8/25/2014,414.1,9.001,3.039,27.354039,Regular,46.00599933,0.066056602,38661.7,914.149,3162.093072,42.09762304,0.081788775,Speedway,46.9,0.894000667,3.459056535,78.2
9/15/2014,406.2,9.094,2.959,26.909146,Regular,44.66681328,0.066246051,39067.9,923.243,3189.002218,42.12292972,0.081627173,Kroger,47.1,2.433186717,3.454130947,59.5
9/30/2014,396.3,9.129,3.189,29.112381,Regular,43.41110746,0.073460462,39464.2,932.372,3218.114599,42.13554247,0.081545162,Kroger,46.7,3.28889254,3.451535009,62
10/22/2014,397.7,9.328,2.859,26.668752,Regular,42.63507719,0.06705746,39861.9,941.7,3244.783351,42.1404906,0.081400619,UDF,45.1,2.464922813,3.445665659,46.9
11/5/2014,413.2,9.262,2.879,26.665298,Regular,44.61239473,0.064533635,40275.1,950.962,3271.448649,42.16456599,0.081227574,UDF,46,1.387605269,3.440146556,50
11/17/2014,398.9,9.081,2.899,26.325819,Regular,43.9268803,0.065996037,40674,960.043,3297.774468,42.18123563,0.081078194,Speedway,45.2,1.2731197,3.435027877,28.6
11/25/2014,345.8,9.003,2.899,26.099697,Regular,38.40941908,0.075476278,41019.8,969.046,3323.874165,42.14619327,0.08103097,UDF,40.7,2.290580917,3.430047867,36.7
12/7/2014,345.6,8.738,2.139,18.690582,Regular,39.55138476,0.054081545,41365.4,977.784,3342.564747,42.12300467,0.080805812,Speedway,41.6,2.048615244,3.418510373,33
12/30/2014,360.8,9.013,1.869,16.845297,Regular,40.03106624,0.046688739,41726.2,986.797,3359.410044,42.10389776,0.080510807,Kroger,42.2,2.168933762,3.40435778,25.4
2/2/2015,338.8,8.725,2.059,17.964775,Regular,38.83094556,0.05302472,42065,995.522,3377.374819,42.0752128,0.080289429,Speedway,41.1,2.269054441,3.392566733,25.9
2/12/2015,321.7,8.765,2.359,20.676635,Regular,36.70279521,0.064273034,42386.7,1004.287,3398.051454,42.02832457,0.08016787,Speedway,39.2,2.497204792,3.383546191,26.3
3/3/2015,310.7,9.93,2.039,20.24727,Regular,31.28902316,0.065166624,42697.4,1014.217,3418.298724,41.92317818,0.080058709,AAFES,37.4,6.110976838,3.370382003,26.4
3/13/2015,408.5,9.404,2.199,20.679396,Regular,43.43896214,0.050622756,43105.9,1023.621,3438.97812,41.93710367,0.079779755,Kroger,42.7,0.738962144,3.359620524,46.1
3/22/2015,396.5,9.051,2.339,21.170289,Regular,43.80731411,0.05339291,43502.4,1032.672,3460.148409,41.9534954,0.079539253,Speedway,45.9,2.092685891,3.35067515,40
3/30/2015,386.7,8.931,1.999,17.853069,Regular,43.29862277,0.04616775,43889.1,1041.603,3478.001478,41.9650289,0.079245222,Meijer,44.4,1.101377225,3.339085504,46.4
4/10/2015,414,8.905,2.399,21.363095,Regular,46.49073554,0.051601679,44303.1,1050.508,3499.364573,42.00339264,0.078986901,Kroger,48.3,1.809264458,3.331116539,61
4/19/2015,368.7,7.84,2.419,18.96496,Regular,47.02806122,0.051437375,44671.8,1058.348,3518.329533,42.04061424,0.07875952,Shell,48.4,1.371938776,3.324359788,62.5
4/28/2015,407.9,9.18,2.179,20.00322,Regular,44.4335512,0.049039519,45079.7,1067.528,3538.332753,42.06119184,0.078490601,Speedway,47.5,3.066448802,3.314510489,49.3
5/10/2015,425.1,9.235,2.499,23.078265,Regular,46.03140227,0.054289026,45504.8,1076.763,3561.411018,42.09524287,0.078264513,Kroger,47.7,1.668597726,3.307516155,74.9
5/19/2015,436.6,9.161,2.629,24.084269,Regular,47.65855256,0.055163236,45941.4,1085.924,3585.495287,42.1421757,0.078044972,BP,49.1,1.44144744,3.301792102,62.9
5/28/2015,399.1,8.503,2.299,19.548397,Regular,46.9363754,0.0489812,46340.5,1094.427,3605.043684,42.17942357,0.077794665,UDF,49,2.063624603,3.294001047,72.9
6/9/2015,416.6,8.858,2.639,23.376262,Regular,47.03093249,0.056112007,46757.1,1103.285,3628.419946,42.21837513,0.077601475,Kroger,48.4,1.36906751,3.288742207,65.5
7/9/2015,419.6,8.917,2.389,21.302713,Regular,47.05618482,0.050769097,47176.7,1112.202,3649.722659,42.25716192,0.077362822,BP,49.4,2.343815184,3.281528588,73.1
7/30/2015,433.9,9.361,2.499,23.393139,Regular,46.35188548,0.053913664,47610.6,1121.563,3673.115798,42.29133807,0.077149118,UDF,48.9,2.548114518,3.274997301,76.2
8/12/2015,410.8,8.774,2.699,23.681026,Regular,46.82015044,0.05764612,48021.4,1130.337,3696.796824,42.32649201,0.076982279,UDF,47.5,0.679849556,3.270526245,68.3
8/23/2015,397,8.841,2.059,18.203619,Regular,44.90442258,0.045852945,48418.4,1139.178,3715.000443,42.34649897,0.076727039,UDF,48.8,3.895577423,3.26112376,72.1
9/1/2015,435.8,9.6,1.999,19.1904,Regular,45.39583333,0.044034878,48854.2,1148.778,3734.190843,42.37198136,0.076435411,Kroger,49.6,4.204166667,3.250576563,75.5
9/12/2015,422.5,8.493,2.269,19.270617,Regular,49.74685035,0.045610928,49276.7,1157.271,3753.46146,42.42610417,0.076171121,Kroger,45.3,4.446850347,3.243372952,58.8
9/22/2015,391.3,8.491,1.799,15.275309,Regular,46.08408904,0.039037335,49668,1165.762,3768.736769,42.45274764,0.075878569,Speedway,48.3,2.215910965,3.232852648,63.3
10/1/2015,421.3,8.961,2.459,22.035099,Regular,47.01484209,0.052302632,50089.3,1174.723,3790.771868,42.48754813,0.075680272,Kroger,50.2,3.185157906,3.22694956,55.9
10/25/2015,412.4,10.057,1.079,10.851503,Regular,41.00626429,0.026313053,50501.7,1184.78,3801.623371,42.47497426,0.075277137,UDF,45.8,4.793735706,3.208716699,55.2
11/14/2015,445.4,9.047,1.979,17.904013,Regular,49.23178954,0.040197604,50947.1,1193.827,3819.527384,42.52617842,0.074970457,Kroger,45.5,3.731789543,3.199397722,38.2
11/24/2015,395.3,9.451,1.899,17.947449,Regular,41.82626177,0.045402097,51342.4,1203.278,3837.474833,42.52068101,0.074742802,Meijer,44.4,2.573738229,3.189183907,37.7
12/9/2015,381.4,9.291,1.469,13.648479,Regular,41.05047896,0.03578521,51723.8,1212.569,3851.123312,42.50941596,0.074455537,Speedway,43.8,2.749521042,3.176003437,46.7
12/18/2015,391,8.715,1.839,16.026885,Regular,44.86517499,0.040989476,52114.8,1221.284,3867.150197,42.5262265,0.074204452,Kroger,46.1,1.234825014,3.166462671,30.8
12/31/2015,356.6,8.754,1.999,17.499246,Regular,40.7356637,0.049072479,52471.4,1230.038,3884.649443,42.51348332,0.074033653,Speedway,43.2,2.464336303,3.158154011,33.4
1/8/2016,375.7,10.531,1.099,11.573569,Regular,35.67562435,0.030805347,52847.1,1240.569,3896.223012,42.45543779,0.073726335,UDF,43.2,7.524375653,3.140674168,38.4
1/17/2016,408.8,8.996,1.199,10.786204,Regular,45.44241885,0.026385039,53255.9,1249.565,3907.009216,42.47694198,0.073362937,Kroger,41.1,4.342418853,3.126695463,24
1/26/2016,326.8,8.83,1.799,15.88517,Regular,37.01019253,0.048608231,53582.7,1258.395,3922.894386,42.43858248,0.073211958,Kroger,39.9,2.889807475,3.11737919,39.6
2/3/2016,338.2,7.974,1.599,12.750426,Regular,42.41284174,0.037700846,53920.9,1266.369,3935.644812,42.4384204,0.072989227,UDF,44.1,1.687158264,3.107818347,53.7
2/10/2016,355.1,8.88,1.349,11.97912,Regular,39.98873874,0.033734497,54276,1275.249,3947.623932,42.42136242,0.072732403,UDF,43.3,3.311261261,3.095571086,16.5
2/17/2016,334.9,8.703,1.559,13.567977,Regular,38.48098357,0.040513517,54610.9,1283.952,3961.191909,42.39465338,0.072534822,UDF,39.6,1.119016431,3.08515576,31.7
2/26/2016,375.8,8.959,1.879,16.833961,Regular,41.94664583,0.044795,54986.7,1292.911,3978.02587,42.39154899,0.072345237,UDF,44.4,2.453354169,3.076797916,29.9
3/13/2016,385.7,8.732,1.959,17.105988,Regular,44.17086578,0.0443505,55372.4,1301.643,3995.131858,42.40348544,0.072150238,UDF,45,0.829134219,3.06929923,54.5
4/5/2016,402.6,9.241,1.959,18.103119,Regular,43.56671356,0.044965522,55775,1310.884,4013.234977,42.41168555,0.071954011,Kroger,45.9,2.333286441,3.061472241,30.9
4/14/2016,370.8,8.674,2.1139,18.3359686,Regular,42.74844362,0.049449754,56145.8,1319.558,4031.570946,42.4138992,0.071805388,UDF,44.5,1.751556375,3.055243457,47.7
4/28/2016,397.6,9.2,2.399,22.0708,Regular,43.2173913,0.05551006,56543.4,1328.758,4053.641746,42.41946239,0.071690803,UDF,44.7,1.482608696,3.050699786,55.8
5/7/2016,377,8.884,1.669,14.827396,Regular,42.43583971,0.039329963,56920.4,1337.642,4068.469142,42.41957116,0.071476468,Speedway,44.1,1.664160288,3.041523174,62.3
5/18/2016,389.2,9.253,2.459,22.753127,Regular,42.06203393,0.058461272,57309.6,1346.895,4091.222269,42.41711492,0.071388079,Kroger,44.8,2.737966065,3.037521313,56.2
5/24/2016,410.5,8.846,2.579,22.813834,Regular,46.40515487,0.055575722,57720.1,1355.741,4114.036103,42.44313626,0.071275623,UDF,47.1,0.694845128,3.034529532,68
6/28/2016,376.6,8.994,2.349,21.126906,Regular,41.87235935,0.05609906,58096.7,1364.735,4135.163009,42.43937468,0.071177244,UDF,42.9,1.027640649,3.030011694,74.6
7/13/2016,357.2,9.138,1.579,14.428902,Regular,39.08951631,0.040394462,58453.9,1373.873,4149.591911,42.41709387,0.070989137,Meijer,41.6,2.510483694,3.020360623,79
8/4/2016,358.8,9.236,1.919,17.723884,Regular,38.84798614,0.04939767,58812.7,1383.109,4167.315795,42.3932604,0.070857413,Kroger,40.7,1.852013859,3.013006057,79.6
8/12/2016,386.7,8.98,2.239,20.10622,Regular,43.0623608,0.051994363,59199.4,1392.089,4187.422015,42.39757659,0.070734197,Kroger,44.7,1.637639198,3.008013148,82.9
8/22/2016,367.9,8.752,2.339,20.470928,Regular,42.03610603,0.055642642,59567.3,1400.841,4207.892943,42.39531824,0.070640988,Meijer,43.3,1.263893967,3.003833371,66.6
8/30/2016,360.1,9.337,2.139,19.971843,Regular,38.56699154,0.055461936,59927.4,1410.178,4227.864786,42.36997032,0.070549778,UDF,41.1,2.533008461,2.998107179,76
9/12/2016,410.1,9.475,2.159,20.456525,Regular,43.2823219,0.049881797,60337.5,1419.653,4248.321311,42.3760595,0.070409303,Marathon,45.1,1.8176781,2.992506838,66
9/22/2016,395.8,9.273,2.189,20.298597,Regular,42.68305834,0.051284985,60733.3,1428.926,4268.619908,42.37805177,0.070284669,UDF,44.4,1.716941659,2.987292489,73.6
10/5/2016,379.5,9.097,1.699,15.455803,Regular,41.71704958,0.040726754,61112.8,1438.023,4284.075711,42.37387024,0.07010112,Speedway,43.7,1.982950423,2.979142691,67.3
10/7/2016,129.6,2.722,2.309,6.285098,Regular,47.61204996,0.048496127,61242.4,1440.745,4290.360809,42.38376673,0.0700554,Kroger,47.2,0.412049963,2.977876591,67.4
10/10/2016,400.1,8.569,2.219,19.014611,Regular,46.69156261,0.047524646,61642.5,1449.314,4309.37542,42.40923637,0.06990916,Kroger,48.8,2.108437391,2.973389769,53.2
10/20/2016,395.7,8.947,1.949,17.437703,Regular,44.22711523,0.044067988,62038.2,1458.261,4326.813123,42.42038977,0.069744337,Wal Mart,46.8,2.572884766,2.967104738,59.5
10/31/2016,395.9,9.247,2.099,19.409453,Regular,42.81388558,0.049026151,62434.1,1467.508,4346.222576,42.42286925,0.069612961,Meijer,45.6,2.786114415,2.961634673,51.2
11/10/2016,414.6,8.899,1.999,17.789101,Regular,46.58950444,0.042906659,62848.7,1476.407,4364.011677,42.44798352,0.069436785,Meijer,48.3,1.710495561,2.955832421,45
11/22/2016,366,9.225,2.599,23.975775,Premium,39.67479675,0.065507582,63214.7,1485.632,4387.987452,42.43076347,0.069414036,Meijer,43.6,3.925203252,2.953616677,30.8
12/6/2016,393.2,9.229,1.989,18.356481,Regular,42.60483259,0.046684845,63607.9,1494.861,4406.343933,42.43183814,0.069273533,BP,44.8,2.195167407,2.947661309,N/A
12/21/2016,334,8.855,2.259,20.003445,Regular,37.71880294,0.059890554,63941.9,1503.716,4426.347378,42.40408428,0.069224521,UDF,39.2,1.481197064,2.943605959,N/A
1/9/2017,332,8.847,2.429,21.489363,Regular,37.52684526,0.064726997,64273.9,1512.563,4447.836741,42.37555725,0.069201289,Speedway,39.6,2.073154742,2.940596022,N/A
One of the things I tried was
plot(factor(Gas.Source),MPG)
It's exactly what you'd expect. Some of the factor levels have very few (or one) observations and so rather than a box and whicker you just get a black line.
I understand this is exactly what I asked it to do, as some of those sources had very few observations. So what I'd like to do is efficiently remove the measurements associated with factor levels where there aren't enough observations to really produce a box and whisker...
I'm guessing I could do this by creating a new dataframe where I've used logical subscripting to select only those rows corresponding to a factor level that has a count that's greater than X....but I'm not sophisticated enough to figure that out yet.
Found what I was looking for here
Given that the original data was in a dataframe called mileage
tbl <- table(mileage$Gas.Source)
new.Mileage <- droplevels(mileage[mileage$Gas.Source %in% names(tbl)[tbl>10],,drop=FALSE])
new.Mileage now has only those rows where there were more than 10 observations at that factor level (i.e. from that gas source)