This is the output of dput(your data)
structure(list(Ca = c(NA, NA, 24.4, NA, 21.4, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 28, 32, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 34.7, NA, 42.5, NA, 26, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 0.6, 21.4, NA, 48.3, 63.5, NA, NA, 28.7, NA, NA, NA, NA, 64.3, 23), Cl = c(1.58, 5.6, 3, NA, 1, 5, 1.2, 4, 4, 8.4, 1, 1.4, 4.9, 1.7, 2, 1.6, 3.3, 2.2, 9, 1, 2, 1, 1, 5, 4, 3, 2.27, 1.76, 5.81, 4.23, 4.23, 6.25, 6.72, 4, NA, 5, 5.8, 5.8, 2.2, 5.4, 5.4, 4.8, 8, 1, 4.8, 5.9, 5.9, 13, 5.6, 1.2, NA, NA, NA, 3, 7, NA, NA, 2, NA, NA, NA, NA, 7, 4.1), Cond = c(NA, NA, 190, 187, 184, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 248, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 304, 354, 379, NA, 300, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 2.2, 187, 285, 378, 533, 207, 262, 244, 238, 280, 380, 402, 636, 300), Mg = c(NA, NA, 10, NA, 9.1, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 11, 12, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 17.4, NA, 21.1, NA, 24, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 9.5, NA, 22.1, 29.9, NA, NA, 12.6, NA, NA, NA, NA, 32.4, 21), Na = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 4L, 4L, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), SO4 = c(9.4, 6.5, 9, NA, 7, 55, 6.8, 105, 15.6, 8.4, 8.8, 19.4, 37, 12, 10, 9.1, 34, 11, 69, 18, 9, 13, 9, 7, 6, 5, 7.8, 7.8, 7.5, 6, 7.3, 7, 7.5, 6, 7, 7, 5.6, 5.6, 5.4, 11, 10.5, 9.9, 11.7, 8.4, 12.1, 16, 20, 7.6, 17, 6.5, NA, 8, 22, 24, 44, NA, 13, 13, 12, 18, 23, 23, 73, 4), TDS = c(105L, 181L, 112L, 144L, 114L, 308L, 96L, 430L, 108L, 108L, 125L, 129L, 360L, 140L, 95L, 120L, 280L, 130L, 352L, 148L, 107L, 125L, 139L, 188L, 201L, 178L, 197L, 187L, 182L, 165L, 186L, 191L, 190L, 176L, 175L, 220L, 163L, 163L, 152L, 221L, 171L, 204L, 174L, 190L, 174L, 210L, 190L, 180L, 200L, 180L, NA, 120L, 135L, 228L, 14L, NA, 156L, 140L, 128L, 160L, 215L, 230L, 316L, 163L)), .Names = c("Ca", "Cl", "Cond", "Mg", "Na", "SO4", "TDS"), class = "data.frame", row.names = c(NA, -64L)) B77S wrote: > > Please see ?dput > > use dput(your data) and paste the output into a reply, thanks. > > This way we know what you are working with. > > > > > Rich Shepard wrote: >> >> I would appreciate pointers on what I should read to understand this >> output: >> >> summary(lm(TDS ~ Cond + Ca + Cl + Mg + Na + SO4)) >> >> Call: >> lm(formula = TDS ~ Cond + Ca + Cl + Mg + Na + SO4) >> >> Residuals: >> ALL 1 residuals are 0: no residual degrees of freedom! >> >> Coefficients: (6 not defined because of singularities) >> Estimate Std. Error t value Pr(>|t|) >> (Intercept) 125 NA NA NA >> Cond NA NA NA NA >> Ca NA NA NA NA >> Cl NA NA NA NA >> Mg NA NA NA NA >> Na NA NA NA NA >> SO4 NA NA NA NA >> >> Residual standard error: NaN on 0 degrees of freedom >> (63 observations deleted due to missingness) >> >> When I look at the summary for the data frame used for this model I do >> not >> see an excessive number of missing values or indications why there are no >> residual degrees of freedom. The same model applied to 8 other data >> frames >> did not produce similar results. >> >> Puzzled, >> >> Rich >> >> ______________________________________________ >> R-help@ 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. >> > -- View this message in context: http://r.789695.n4.nabble.com/Interpreting-Multiple-Linear-Regression-Summary-tp4020516p4021355.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.