Is it possible to transform gbm.step result into a dataframe?

Question

I want to insert a scale break in my chart result but I am trying for days and I don't know how to do it. I guess it's only possible if I have a data frame because when I try it all the options that I found online it doesn't work because I have a gbm result. So I guess if I could transform my result into a data frame I would be able to plot with the scale break I need.

    ina <- gbm.step(data=bonaci, gbm.x = 2:5, gbm.y = 1, 
                family = "gaussian", tree.complexity = 5, 
                learning.rate = 0.0001, bag.fraction = 0.5)
m<-gbm.plot(ina,
         variable.no = 1, 
         smooth= TRUE, 
         rug= TRUE, 
         n.plots= 4, 
         common.scale= FALSE, 
         write.title= FALSE,
         y.label= NULL,
         x.label= NULL, 
         show.contrib= FALSE, 
         cex.axis= 0.7, 
         cex.lab= 0.8, 
         las = 2, #direcao legenda eixo x. 1 = horizontal, 2 = vertical
         plot.layout=c(1,1)

When I try this code whith plotrix package:

from <- -1000
to <- -4000
gap.plot(m, gap=c(from,to), xlab="index", ylab="value")

This error appears:

Error in ylim[2] - gapsize[1] : 
  argumento não-numérico para operador binário

I would like to add a break in the y-axis scale so that values closer to zero can appear.