I received a private request for my complete dataset from my previous questions. In gratitude to the developers of R, and especially to the helpful members of r-help, I'm happy to attach it. Anyone is free to use this dataset in any manner they wish, including published books. Attribution is not required, or even desired. Explanatory notes on dataset: This data is collected from monthly utility bills for my 80 year old house in northern Baltimore City, Maryland, USA. The fields are: start: date of start of billing period therms: integer number of therms used in this billing period gas: Total cost of gas (including delivery and commodity charges) for natural gas KWHs: integer number of KWH used in this billing period elect: Total cost of electricity (including delivery and commodity charges) temp: average daily outdoor temperature in degrees Fahrenheit, as printed on the bill days: number of days in billing period. Heating system is a 10-15 year old natural gas steam boiler supplying iron radiators. Hot water heater, clothes dryer and stove and oven are also natural gas. Air conditioning is by various numbers of window units. If surface area of house is desired, I can add this at a later time. Some interesting points in time: 22-Apr-04: Date when I upgraded 2 failed, older storm windows to more modern ones. 1-Sep-04: Date when I upgraded 4 failed, older storm windows to more modern ones. Interesting question: Did upgrading the windows significantly change the heat loss? last week of July 1999: Spouse moved in; both adults absent during the work day, setback thermostat used. Interesting question: Is there a discernable difference in the energy costs for heating between a single person and a couple? What's the heating "cost" of adding a spouse or roommate? 18-Dec-2006: Brought home son; spouse and son home during the day, setback thermostat no longer used. Interesting question: What's the "cost" of adding a child? If I could supply any more information that would make this dataset more useful or interesting, please let me know. I'm having fun 'playing' with these data; I hope you and your students do, too. -Kevin start therms gas KWHs elect temp days 10-Jun-98 9 16.84 613 63.80 75 40 20-Jul-98 6 15.29 721 74.21 76 29 18-Aug-98 7 15.73 597 62.22 76 29 16-Sep-98 42 35.81 460 43.98 70 33 19-Oct-98 105 77.28 314 31.45 57 29 17-Nov-98 106 77.01 342 33.86 48 30 17-Dec-98 200 136.66 298 30.08 40 33 19-Jan-99 144 107.28 278 28.37 37 30 18-Feb-99 179 122.80 253 26.21 39 29 16-Apr-99 57 49.81 315 31.56 54 32 18-May-99 8 17.11 373 40.57 64 30 17-Jun-99 6 15.77 596 62.12 73 33 20-Jul-99 6 15.88 723 74.41 77 29 18-Aug-99 7 16.69 532 55.94 76 30 17-Sep-99 45 42.20 551 50.81 66 32 19-Oct-99 107 82.87 367 36.00 55 29 16-Dec-99 245 166.94 490 46.56 42 33 18-Jan-00 267 183.35 395 38.40 33 30 17-Feb-00 147 99.77 448 42.95 38 32 20-Mar-00 94 72.39 395 38.40 49 29 18-Apr-00 50 46.87 363 35.65 56 29 17-May-00 25 28.63 457 48.68 64 33 19-Jun-00 5 16.53 525 55.26 70 31 20-Jul-00 7 18.23 511 51.64 74 28 17-Aug-00 8 19.22 538 53.95 72 33 19-Sep-00 51 60.78 390 34.98 65 30 19-Oct-00 91 94.72 364 33.18 56 28 16-Nov-00 241 226.93 465 40.19 44 33 19-Dec-00 289 287.52 423 37.28 33 31 19-Jan-01 174 197.69 348 32.07 33 28 16-Feb-01 145 163.59 338 31.38 39 32 20-Mar-01 121 122.53 346 31.93 45 29 18-Apr-01 47 50.94 370 33.60 55 29 17-May-01 16 23.99 460 48.11 65 34 20-Jun-01 7 17.25 447 46.98 71 29 19-Jul-01 6 15.81 589 59.40 75 32 20-Aug-01 6 15.66 433 45.76 74 29 18-Sep-01 44 39.27 419 36.24 66 31 19-Oct-01 97 74.58 356 31.98 56 27 15-Nov-01 120 91.27 484 40.65 51 33 18-Dec-01 183 154.37 393 34.45 43 30 17-Jan-02 170 134.35 394 34.52 38 33 19-Feb-02 142 120.94 331 30.27 43 28 19-Mar-02 88 71.53 393 34.45 48 30 18-Apr-02 47 48.19 389 34.18 57 29 20-Jun-02 5 15.92 625 61.40 78 32 22-Jul-02 5 15.90 656 64.04 80 25 19-Aug-02 6 16.65 502 50.86 73 34 19-Sep-02 22 29.40 418 36.15 64 29 18-Oct-02 120 108.07 413 35.81 48 31 18-Nov-02 203 162.15 414 35.88 35 30 18-Dec-02 205 170.99 380 33.58 35 30 17-Jan-03 285 233.82 418 36.15 27 28 14-Feb-03 234 228.27 400 34.93 34 31 17-Mar-03 122 134.71 428 36.83 50 30 16-Apr-03 57 74.81 317 29.32 59 30 16-May-03 39 49.29 385 40.83 62 32 17-Jun-03 8 18.42 323 35.52 74 34 21-Jul-03 6 17.17 863 81.77 76 29 19-Aug-03 6 17.26 764 73.29 72 29 17-Sep-03 40 44.57 545 44.75 62 30 17-Oct-03 98 92.39 411 35.67 53 31 17-Nov-03 193 176.25 615 49.46 41 29 16-Dec-03 247 248.99 309 28.78 35 31 16-Jan-04 306 313.66 316 29.25 27 28 13-Feb-04 185 188.46 319 29.45 42 32 16-Mar-04 162 155.90 321 29.59 46 31 16-Apr-04 36 45.58 327 29.99 65 31 17-May-04 7 19.18 397 41.87 71 30 16-Jun-04 8 20.35 435 45.12 74 29 15-Jul-04 6 18.23 371 40.28 74 34 18-Aug-04 7 19.13 402 43.00 73 31 18-Sep-04 30 42.57 407 36.11 61 28 18-Oct-04 93 115.80 267 26.41 51 27 12-Nov-04 142 177.04 395 35.26 46 32 14-Dec-04 216 255.96 500 42.57 38 31 14-Jan-05 300 326.58 423 37.22 31 32 17-Jan-06 197 284.61 419 36.96 39 28 15-Dec-05 234 377.98 514 43.55 39 33 14-Nov-05 165 296.39 239 24.48 38 31 17-Oct-05 79 150.51 231 23.90 53 28 19-Sep-05 8 24.46 222 23.39 66 28 17-Aug-05 8 22.65 410 43.71 74 33 18-Jul-05 7 20.12 633 63.20 79 30 16-Jun-05 9 21.86 530 54.18 75 32 17-May-05 29 44.15 335 37.14 67 30 18-Apr-05 65 80.85 220 23.15 58 29 16-Mar-05 126 141.82 289 27.93 49 30 15-Feb-05 226 251.89 257 25.71 36 29 14-Feb-06 183 257.23 332 30.93 41 30 16-Mar-06 115 146.31 298 28.56 51 33 18-Apr-06 36 54.55 291 28.06 59 28 17-May-06 22 37.98 374 40.55 68 34 19-Jun-06 7 20.68 614 83.19 78 29 18-Jul-06 6 19.94 746 115.47 80 30 17-Aug-06 11 26.08 534 84.89 72 33 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.