How to merge a BEDMatrix with a 'regular' matrix object in R

Question

I am dealing with a new R object class for me, a BEDMatrix object. I have created a BEDMatrix from the standard plink files. Now I want to merge it with a regular matrix object in R. I have tried the functions merge() and join(), but all of them seem not to support the BEDMatrix object. Here is the code:

#----------------------- creating BEDMatrix--------------------------------------
library(BGData)

chr29 <- BEDMatrix("path to plink file")

#--------------------------------reading excel file---------------------------------------

library(readxl)

sheets <- excel_sheets(path = 'path to excel file')

Excel_rawTAUINDanimalList <- read_excel(path = 'path to excel file', sheet = "rawTAUIND-animalList")

# -------------- changing excel file to matrx ----------------------------------------------

excel_matrix <- as.matrix(Excel_rawTAUINDanimalList)


# ------------------------ trying to merge ------------------------------------------------

merged <- merge(chr29, excel_matrix, by.x = 1, by.y = 1, all.x = TRUE, all.y = TRUE)

I get this error:

can't covert ‘structure("BEDMatrix", package = "BEDMatrix")’ to data.frame

Any help would be appreciated.

Thanks,

Qba Liu