I am doing multiple linear regression analysis in R and I got the following summary:
Call: lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + X10 + X11 + X12 + X13) Residuals: ALL 20 residuals are 0: no residual degrees of freedom! Coefficients: (151 not defined because of singularities) Estimate Std. Error t value Pr(>|t|) (Intercept) -15462.94 NA NA NA X1 63.31 NA NA NA X2 1363.12 NA NA NA X31,266,019,376 5518.54 NA NA NA X31,483,786,035 29894.78 NA NA NA X31,619,000,000 39338.01 NA NA NA X31,687,000,000 65308.07 NA NA NA X31,720,264,324 35548.79 NA NA NA X31,749,000,000 31693.75 NA NA NA ....................................................... X13692,062,808 NA NA NA NA X13693,179,733 NA NA NA NA X13724,817,439 NA NA NA NA Residual standard error: NaN on 0 degrees of freedom Multiple R-squared: 1, Adjusted R-squared: NaN F-statistic: NaN on 19 and 0 DF, p-value: NA
Could anybody explain what does that result mean? And what should I do?
Another question. What should I do if the following error appears:
Error in step(model) : number of rows in use has changed: remove missing values?