```
# NOT RUN {
data(CAex)
str(CAex) # of class "dgCMatrix"
image(CAex)# -> it's a simple band matrix with 5 bands
## and the eigen values are basically 1 (42 times) and 0 (30 x):
zapsmall(ev <- eigen(CAex, only.values=TRUE)$values)
## i.e., the matrix is symmetric, hence
sCA <- as(CAex, "symmetricMatrix")
## and
stopifnot(class(sCA) == "dsCMatrix",
as(sCA, "matrix") == as(CAex, "matrix"))
# }
```

Run the code above in your browser using DataLab