Using dplyr filter in a Shiny app

Question

I'm in the early stages of building a Shiny app to plot some data based on user selections. My data begins:

Price,Mileage,Make,Model,Trim,Type,Cylinder,Liter,Doors,Cruise,Sound,Leather
17314.10313,8221,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,1
17542.03608,9135,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,0
16218.84786,13196,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,0
16336.91314,16342,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,0,0
16339.17032,19832,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,0,1
15709.05282,22236,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,0
15230.00339,22576,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,0
15048.04218,22964,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,0
14862.09387,24021,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,0,1
15295.01827,27325,Buick,Century,Sedan 4D,Sedan,6,3.1,4,1,1,1
21335.85248,10237,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,0,0
20538.08751,15066,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,0
20512.09409,16633,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,0
19924.15905,19800,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,1
19774.24907,23359,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,1
19344.16554,23765,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,0
19105.13012,24008,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,0,0
18543.42705,26034,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,1
17808.199,32896,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,0
17968.83828,34665,Buick,Lacrosse,CX Sedan 4D,Sedan,6,3.6,4,1,1,1
22358.87768,8970,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,1,0
23785.92253,10577,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,1,1
22926.09037,14363,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,1,1
21895.75878,16508,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,1
21273.06171,18908,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,0
21460.01395,19467,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,1
21183.12359,21394,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,0
20406.0995,22596,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,0
21058.13958,24469,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,1,1
19556.89932,25245,Buick,Lacrosse,CXL Sedan 4D,Sedan,6,3.6,4,1,0,0
23447.68656,15755,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,0
23547.23944,16235,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,0
23016.00801,18147,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,1
22230.0275,22102,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,0,1
22625.07357,23612,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,0,1
21799.1721,24439,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,0,0
21341.25721,25212,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,1
21683.03146,26779,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,0
20986.01602,27096,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,0,0
20902.10379,29649,Buick,Lacrosse,CXS Sedan 4D,Sedan,6,3.8,4,1,1,1
20698.07708,2992,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,0,1
20099.25684,10036,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,1
18145.12649,18339,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,0
17944.85692,19592,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,0,0
19027.86231,21797,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,0,1
18348.89857,23852,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,0
17750.88457,25040,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,0
17772.96968,25052,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,0
17394.0214,25464,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,0
17645.74504,27830,Buick,Lesabre,Custom Sedan 4D,Sedan,6,3.8,4,1,1,1
21908.36662,17353,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,0,0
21956.34266,17787,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,0
21646.11692,19562,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,1
21575.45683,20137,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,0
20952.2178,20158,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,0
21562.04758,23767,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,0,1
19981.12791,24323,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,0
19425.84862,27839,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,0
19191.98962,29187,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,1
19641.7419,31324,Buick,Lesabre,Limited Sedan 4D,Sedan,6,3.8,4,1,1,1
25589.98315,2308,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,0
25098.62906,10014,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,0
23420.70695,18910,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,0,1
22661.04849,20105,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,0,0
23493.0823,20453,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,0
22435.20282,22287,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,1
21878.12,23237,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,0
23077.56591,23798,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,0,1
21698.01475,25489,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,1
21831.82292,25564,Buick,Park Avenue,Sedan 4D,Sedan,6,3.8,4,1,1,1
26831.19404,4695,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,0
26060.33535,9795,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,0
26781.81465,12052,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,0
26302.07428,13050,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,0
26190.27147,17335,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,0,1
25508.21096,17480,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,0
23348.01695,24027,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,0,1
23406.68982,25387,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,0,1
23159.54378,25869,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,0,0
21536.74173,37128,Buick,Park Avenue,Special Ed Ultra 4D,Sedan,6,3.8,4,1,1,1
51154.04722,2202,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,1,1
49248.15897,6685,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,0,1
46747.67327,15343,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,1,1
44130.61706,21341,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,0,1
44084.91421,21367,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,1,1
43892.46788,23371,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,0,1
44300.63996,23751,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,0,1
42677.60112,24052,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,0,1
43374.05242,25199,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,1,1
40619.07227,30082,Cadillac,CST-V,Sedan 4D,Sedan,8,5.7,4,1,1,1
33417.96501,6598,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
30957.08075,10625,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
31431.13037,11013,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
30781.51563,14937,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
30646.4377,17094,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
30792.14903,17870,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
30392.75016,18449,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
28817.08185,21039,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,0,1
29275.20871,21056,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
28040.12853,27484,Cadillac,CTS,Sedan 4D,Sedan,6,2.8,4,1,1,1
39801.55135,14095,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
40335.73731,14743,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
39307.00916,16041,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
38600.23956,17138,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
38445.89717,18661,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
36077.79612,21966,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
35866.58271,24415,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,1,1
35338.65369,25163,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
36154.30355,25339,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,1,1
34685.66298,25421,Cadillac,Deville,DHS Sedan 4D,Sedan,8,4.6,4,1,0,1
42820.32902,5499,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
41378.04809,8125,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
40856.3909,12791,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,1,1
41419.03726,14452,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
37510.25357,21593,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
37215.16938,22211,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
36332.89469,25153,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
36245.15823,26250,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,1,1
32954.14134,36074,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,0,1
32537.18675,41829,Cadillac,Deville,DTS Sedan 4D,Sedan,8,4.6,4,1,1,1
35715.76856,6447,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,0,1
35651.68002,10555,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,1,1
35129.34077,11975,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,1,1
35165.75937,13449,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,1,1
32501.24519,17508,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,0,1
33220.02845,18661,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,0,1
32509.47829,20910,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,0,1
31132.21349,23124,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,1,1
31181.71516,26222,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,0,1
31059.18103,27544,Cadillac,Deville,Sedan 4D,Sedan,8,4.6,4,1,1,1
42741.52367,2846,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,0,1
40966.60741,7476,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
38795.37909,13973,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
38297.46254,16754,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,0,1
37192.89637,19100,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,0,1
36210.123,21778,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,0,1
36633.63382,22042,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
35895.49941,23056,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
34974.37804,25796,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
32038.33956,35326,Cadillac,STS-V6,Sedan 4D,Sedan,6,3.6,4,1,1,1
48310.32954,788,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,0,1
48365.9809,2616,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,1,1
45061.95194,13829,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,1,1
44205.87588,15104,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,0,1
42377.95544,18581,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,0,1
41671.58314,20575,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,0,1
41516.42986,23861,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,1,1
41053.48217,25717,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,1,1
38208.50102,31303,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,1,1
39072.39205,31587,Cadillac,STS-V8,Sedan 4D,Sedan,8,4.6,4,1,0,1
70755.46672,583,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
68566.18719,6420,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
69133.73172,7892,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
66374.30704,12021,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
65281.48124,15600,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
63913.11725,18200,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
60567.54909,23193,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
57154.44344,29260,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
55639.08765,31805,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,0,1
52001.99438,42691,Cadillac,XLR-V8,Hardtop Conv 2D,Convertible,8,4.6,2,1,1,1
12146.18803,10011,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,1
12163.82042,12101,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,1
11472.02276,19699,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,1
11017.16871,20100,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,1,0
11096.85727,20334,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,1,0,0
10386.04022,22225,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,0
11137.04565,22484,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11045.10884,24568,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,1,0,1
10777.05254,27906,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,0
9928.188175,29680,Chevrolet,AVEO,LS Hatchback 4D,Hatchback,4,1.6,4,0,0,1
12649.11089,3629,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,1,0
12314.59122,4142,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,1,0
11318.00809,11156,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,1,1
12409.94909,11981,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,1,1,1
11555.2674,13404,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,1,1,0
11700.11149,15253,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,1,0,0
11215.01865,19945,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,0,0
10144.95208,23963,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,1,1,0
10491.0752,30948,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,1,0
9954.054174,37345,Chevrolet,AVEO,LS Sedan 4D,Sedan,4,1.6,4,0,1,1
11031.12993,20156,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11343.05401,20186,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,1,1,1
11391.21372,21421,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11247.86253,21427,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,1,1,1
10921.94537,23119,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11179.95357,23121,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11394.8864,25107,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11070.06064,25476,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,0,1,1
11013.87137,25746,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,1,1,1
11115.01364,30056,Chevrolet,AVEO,LT Hatchback 4D,Hatchback,4,1.6,4,1,1,1
11918.45607,7278,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,0,0
12408.80615,10213,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,0,1
11302.90299,14627,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,1,0
11615.02102,19014,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,1,1
10805.13009,21013,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,1,1,1
11169.91839,22380,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,1,0
10770.10655,25065,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,1,0
10872.01393,25869,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,0,0
10921.94537,27776,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,1,0,0
9919.048185,34621,Chevrolet,AVEO,LT Sedan 4D,Sedan,4,1.6,4,0,1,0
10813.34352,266,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,1,0,1
11167.861,4716,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,1,1,0
10897.07651,6699,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,0,1,1
10106.01643,14200,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,1,0,0
10354.04385,14521,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,0,1,0
10287.97736,16521,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,1,1,1
9720.97889,20836,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,1,1,0
9506.047937,22169,Chevrolet,AVEO,SVM Hatchback 4D,Hatchback,4,1.6,4,0,0,1

The whole thing is too big to post, but this should be sufficient.

My ui.R file contains

library(shiny)


data <- read.csv("Amstat.csv", header = TRUE)
modelTypes <- unique(data$Model)

# Define UI for application that draws a histogram
shinyUI(fluidPage(

  # Application title
  titlePanel("Car prices"),

  # Sidebar with a slider input for number of bins 
  sidebarLayout(
    sidebarPanel(
      selectInput("Model", 
                  label = "Choose a Model to display",
                  choices = modelTypes),

      selectInput("price",
                  label = "Choose a price",
                  choices = list("Left","Center", "Right"),
                  selected="CENTER")


    ),

    # Show a plot of the generated distribution
    mainPanel(
       plotOutput("carpricePlot")
    )
  )
))

And my server.r contains

library(shiny)
library(magrittr)
library(dplyr)

shinyServer(function(input, output) {

  data <- read.csv("Amstat.csv", header = TRUE)
  amstat1<-data %>% select(Type,Price,Model )%>% filter(Model == input$Model)

  output$carpricePlot <- renderPlot({

    plot(Model,
         Price,
         xlab="Model",
         ylab="prirce",
         pch=20)

  })
})

When I try to run the app, I get an error message

Error in filter_impl(.data, dots) : Operation not allowed without an active reactive context. (You tried to do something that can only be done from inside a reactive expression or observer.)

I'm not grasping something. In other apps I've written as I try to learn Shiny I've accomplished basically the same thing using subset instead of filter...should I just avoid filter in Shiny? Or am I doing something wrong? Well, clearly I'm doing something wrong!

Answer 1

When you use a variable from UI (input$...), you must do it in a reactive:

shinyServer(function(input, output) {

  data <- read.csv("Amstat.csv", header = TRUE)
  amstat1<-reactive({
    data %>% select(Type,Price,Model ) %>% filter(Model == input$Model)
    })

  output$carpricePlot <- renderPlot({
    plot(amstat1()$Model,
         amstat1()$Price,
         xlab="Model",
         ylab="Price",
         pch=20)

  })
})