# rank of matrices depending on parameters

Hi!

I have a question on how to treat objects depending with parameters.

For example, let M be a matrix depending on a parameter - call it t. The rank command just returns the generic rank. I would like to know the rank of the matrix, varying the parameter. In the example,

```
_ = var('t')
M = matrix([[t,0],[0,1]])
M.rank()
```

I would like to get: if t=0, the rank is 1; otherwise is 2. Is there any command for this in Sage? (I've heard about a "full solve" in Mathematica.)

Thanks in advance,