hi guys i have multiple data frames which i want to merge. there are four of them..eg pdf
SampleID UVDose_J RepairHours Day_0 Day_45 Day_90 1 SDM001 1.0 3 485.612 465.142 490.873 2 SDM001 1.0 3 503.658 457.863 487.783 3 SDM001 1.0 2 533.193 451.044 456.973 4 SDM001 1.0 2 538.334 452.887 474.915 5 SDM001 1.0 1 526.034 481.123 477.801 6 SDM001 1.0 1 546.543 472.322 481.546 7 SDM001 1.0 0 NA NA NA 8 SDM001 1.0 0 NA NA NA 9 SDM001 0.5 3 432.134 457.245 497.975 10 SDM001 0.5 3 432.605 450.184 489.468 11 SDM001 0.5 2 450.335 496.520 488.784 12 SDM001 0.5 2 439.590 474.371 470.182 13 SDM001 0.5 1 510.480 489.561 525.029 14 SDM001 0.5 1 487.934 467.258 488.784 15 SDM001 0.5 0 NA NA NA 16 SDM001 0.5 0 NA NA NA 20 SDM002 1.0 3 465.549 528.715 501.374 21 SDM002 1.0 3 458.168 505.480 489.244 22 SDM002 1.0 2 447.317 464.009 478.058 23 SDM002 1.0 2 452.020 438.446 470.996 24 SDM002 1.0 1 441.718 458.760 499.221 25 SDM002 1.0 1 447.017 402.616 548.797 26 SDM002 1.0 0 NA NA NA 27 SDM002 1.0 0 NA NA NA 28 SDM002 0.5 3 421.409 448.870 476.392 29 SDM002 0.5 3 404.089 446.413 477.080 30 SDM002 0.5 2 399.775 432.678 465.015 31 SDM002 0.5 2 427.157 443.418 477.048 32 SDM002 0.5 1 389.674 449.353 482.264 33 SDM002 0.5 1 418.147 455.983 495.486 34 SDM002 0.5 0 NA NA NA 35 SDM002 0.5 0 NA NA NA 39 SDM005 1.0 3 579.836 441.040 476.382 40 SDM005 1.0 3 578.525 443.875 472.867 41 SDM005 1.0 2 564.266 432.116 469.416 42 SDM005 1.0 2 571.045 447.658 458.233 43 SDM005 1.0 1 564.664 427.673 524.122 44 SDM005 1.0 1 568.182 458.039 477.237 45 SDM005 1.0 0 NA NA NA 46 SDM005 1.0 0 NA NA NA 47 SDM005 0.5 3 556.534 424.786 501.658 48 SDM005 0.5 3 474.027 441.418 507.635 49 SDM005 0.5 2 481.355 430.346 468.021 50 SDM005 0.5 2 478.922 466.933 471.025 51 SDM005 0.5 1 505.539 937.759 460.985 52 SDM005 0.5 1 497.913 457.932 493.152 53 SDM005 0.5 0 NA NA NA 54 SDM005 0.5 0 NA NA NA 58 SDM006 1.0 3 589.164 459.578 509.565 59 SDM006 1.0 3 608.477 480.233 519.785 60 SDM006 1.0 2 598.354 449.266 487.058 61 SDM006 1.0 2 617.823 456.908 507.467 62 SDM006 1.0 1 566.477 500.189 526.744 63 SDM006 1.0 1 622.170 462.463 550.675 64 SDM006 1.0 0 NA NA NA 65 SDM006 1.0 0 NA NA NA 66 SDM006 0.5 3 546.472 457.880 468.129 67 SDM006 0.5 3 525.069 444.575 505.154 68 SDM006 0.5 2 569.068 446.196 473.739 69 SDM006 0.5 2 534.205 470.366 476.570 bdf SampleID UVDose_J RepairHours Day_0 Day_45 Day_90 17 SDM001 0.5 B 88.6145 388.3575 198.467 36 SDM002 0.5 B 100.0760 384.9505 234.740 55 SDM005 0.5 B 121.9595 300.3650 241.832 74 SDM006 0.5 B 174.7005 378.3435 291.272 93 SDM007 0.5 B 319.7750 335.4390 110.306 112 SDM008 0.5 B 292.8400 323.0370 172.615 131 SDM010 0.5 B 112.0225 281.0390 562.459 150 SDM011 0.5 B 125.0440 331.4650 230.026 169 SDM012 0.5 B 229.1310 264.5580 234.231 188 SDM013 0.5 B 212.9690 524.0240 420.211 207 SDM014 0.5 B 366.3350 225.0610 203.588 226 SDM016 0.5 B 305.6080 381.5770 155.052 245 SDM017 0.5 B 223.6260 281.7830 182.374 264 SDM018 0.5 B 200.7720 401.6350 193.573 283 SDM019 0.5 B 164.2360 156.9960 175.896 302 SDM023 0.5 B 198.8900 210.0600 215.629 321 SDM024 0.5 B 351.8460 100.0980 185.388 340 SDM026 0.5 B 190.4560 132.8970 160.213 359 SDM028 0.5 B 252.9760 158.2910 120.425 378 SDM029 0.5 B 411.0690 134.1060 138.528 tdf SampleID UVDose_J RepairHours Day_0 Day_45 Day_90 19 SDM001 0.5 T 642.3255 579.6635 537.581 38 SDM002 0.5 T 531.2000 581.0030 557.537 57 SDM005 0.5 T 619.5420 539.9010 548.100 76 SDM006 0.5 T 707.0940 563.1125 575.318 95 SDM007 0.5 T 679.3480 794.3410 332.972 114 SDM008 0.5 T 535.6860 759.0300 452.312 133 SDM010 0.5 T 756.8055 549.2960 916.447 152 SDM011 0.5 T 530.1690 557.1600 564.988 171 SDM012 0.5 T 570.6130 586.7140 643.590 190 SDM013 0.5 T 801.2055 711.1110 846.603 209 SDM014 0.5 T 681.6570 579.3980 464.721 228 SDM016 0.5 T 646.3070 796.6570 461.541 247 SDM017 0.5 T 598.1090 600.5710 380.724 266 SDM018 0.5 T 478.8850 763.9780 487.901 285 SDM019 0.5 T 551.8080 393.5920 427.805 304 SDM023 0.5 T 540.6330 432.2220 521.390 323 SDM024 0.5 T 907.8530 423.7630 606.219 342 SDM026 0.5 T 491.7560 351.3230 397.250 361 SDM028 0.5 T 856.5920 433.1750 521.138 380 SDM029 0.5 T 1016.0070 402.5070 530.783 udf SampleID UVDose_J RepairHours Day_0 Day_45 Day_90 18 SDM001 0.5 U 550.8855 526.7340 529.872 37 SDM002 0.5 U 412.3365 509.4620 550.017 56 SDM005 0.5 U 480.2640 483.4895 542.689 75 SDM006 0.5 U 540.4710 511.0770 560.678 94 SDM007 0.5 U 570.0560 681.3420 319.796 113 SDM008 0.5 U 519.8770 645.7330 388.029 132 SDM010 0.5 U 585.8030 500.4690 807.349 151 SDM011 0.5 U 478.6695 551.5200 558.238 170 SDM012 0.5 U 511.4090 559.7340 616.184 189 SDM013 0.5 U 600.0280 640.7730 742.612 208 SDM014 0.5 U 678.5090 533.0730 437.730 227 SDM016 0.5 U 590.0480 753.8820 439.535 246 SDM017 0.5 U 541.5020 596.2840 358.916 265 SDM018 0.5 U 472.7440 633.3910 475.366 284 SDM019 0.5 U 463.6920 371.9310 395.282 303 SDM023 0.5 U 475.2470 429.0660 447.901 322 SDM024 0.5 U 829.9080 409.1480 542.602 341 SDM026 0.5 U 451.6500 347.2890 352.653 360 SDM028 0.5 U 697.7690 384.7120 520.445 379 SDM029 0.5 U 943.3400 351.4490 527.495 now i want to merge all these data frames and perform calculation like (pdf$Day_0-bdf$Day_0)/(tdf$Day_0-bdf$Day_0) (udf$Day_0-bdf$Day_0)/(tdf$Day_0-bdf$Day_0) please note the Repair hours and UV dose is different please help....really urgent -- View this message in context: http://r.789695.n4.nabble.com/merging-multiple-data-frames-tp2551995p2551995.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org 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.