[R] argument to 'which' is not logical

[S Ellison]

> I'm trying to run the code: inds<-which(c != 0 ), but it gave me error: Error in
> base::which(x, arr.ind, useNames, ...) :   argument to 'which' is not logical

Your coefficients are not a numeric vector. You'll have to sort that out by extracting or testing the individual values. A look at your output _tells you_ that the object is a sparse matrix of class dgCMatrix . Looking that up would tell you that the nonzero elements are in slot x of the object. So it may be unnecessary to ask which are zero; maybe you just need c at x (though I also would recommend you avoid using common function names as variable names)

If you do need to test elements for zeroes, though, note that '==' and '!=' are not usually recommended for comparisons with zero owing to finite numerical representation. So that may well be unwise. See the Note in ?'=='.

S Ellison



> Here is code:
> alphas <- seq(0, 1, by=.002)mses <- numeric(501)mins <- numeric(501)maxes
> <- numeric(501)for(i in 1:501){  cvfits <- cv.glmnet(Train2,
> Train$Item_Outlet_Sales, alpha=alphas[i], nfolds=32)  loc <-
> which(cvfits$lambda==cvfits$lambda.min)  maxes[i] <- cvfits$lambda %>%
> max  mins[i] <- cvfits$lambda %>% min  mses[i] <- cvfits$cvm[loc]}`%ni%`<-
> Negate(`%in%`)c<-coef(cvfits,s='lambda.1se',exact=TRUE)inds<-which(c != 0
> ) Here is the c content looks like: > c33 x 1 sparse Matrix of class
> "dgCMatrix"                                           1(Intercept)                      7.476895931Item_Fa
> t_Content.Low.Fat         .          Item_Fat_Content.Regular         .          Item_Type
> .Breads                 .          Item_Type.Breakfast              .          Item_Type.Canned
>             0.003430669Item_Type.Dairy                 -
> 0.022579673Item_Type.Frozen.Foods          -
> 0.008216547Item_Type.Fruits.and.Vegetables  .          Item_Type.Hard.Drinks
>          .          Item_Type.Health.and.Hygiene     .          Item_Type.Household
>     .          Item_Type.Meat                   .          Item_Type.Others                 .          Item
> _Type.Seafood                .          Item_Type.Snack.Foods            .          Item_Type.S
> oft.Drinks            .          Item_Type.Starchy.Foods          .          Outlet_Establishm
> ent_Year.1987  -
> 0.345927916Outlet_Establishment_Year.1997   1.692678186Outlet_Establishm
> ent_Year.1998  -
> 2.259508290Outlet_Establishment_Year.1999   .          Outlet_Establishment_Y
> ear.2002  -
> 0.032971913Outlet_Establishment_Year.2004   1.756230495Outlet_Establishm
> ent_Year.2007   .          Outlet_Establishment_Year.2009  -
> 0.549210057Outlet_Size.Medium               0.056897825Outlet_Size.Small
>  -
> 1.706006538Outlet_Location_Type.Tier.3      0.373456218Item_Identifier_Com
> binedFD       .          Item_MRP                         0.505435352Item_Weight
> .          Item_Visibility_MeanRatio       -0.007274202
> 	[[alternative HTML version deleted]]
> 
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