[BUG] pt fitting has bug with float32

[njzjz]

pt:

    def forward(
        self,
        xx: torch.Tensor,
    ) -> torch.Tensor:
        """One MLP layer used by DP model.
    
        Parameters
        ----------
        xx : torch.Tensor
            The input.
    
        Returns
        -------
        yy: torch.Tensor
            The output.
        """
        yy = (
>           torch.matmul(xx, self.matrix) + self.bias
            if self.bias is not None
            else torch.matmul(xx, self.matrix)
        )
E       RuntimeError: expected mat1 and mat2 to have the same dtype, but got: double != float

[anyangml]

#3314