rsf2csf
Convert the real Schur form of a matrix to its complex Schur form.
` [Tc,Qc]=rscf2csf(T,Q)`
 Inputs `T` The first output of the function `schur` that returns the Schur form of a matrix. `Q` The second output of the function `schur` that returns the Schur form of a matrix. Outputs `Tc` A possibly complex but strictly upper triangular matrix. `Qc` A possibly complex unitary matrix.

Description
If the pair `(T,Q)` is computed from `[T,Q]=schur(a)` , the outputs of `rsf2csf` also satisfy `Qc'*a*Qc=Tc` . However, only the upper triangular part of `Tc` contains non-zero elements, whereas `T` may contain elements in the sub-diagoanl immediately below the main diagonal.

Example
```>>a=[1 2 3 4 ; 10 12 15 23; 15 18 23 19; 18 25 123 19]
>>a
1          2          3          4
10         12         15         23
15         18         23         19
18         25        123         19

>>[T,Q]=schur(a)
>>//Note that T is upper triangular except for the nozero element T[4,3]
>>// in the lower triangular part.
>>T
85.2031     -13.3272      52.2308      -81.852
2.3093e-014      -0.5539      -5.8584      16.1396
-1.7764e-014 -6.2172e-015     -10.7226      35.6653
-1.4211e-014  7.1054e-015      -0.8419     -18.9266

>>[Tc,Qc]=rsf2csf(T,Q)
>>// Note that Tc is strictly upper triangular.
>>Tc
Columns 1 through 3
85.2031                      -13.3272                       51.0749 +    34.2306i
0                       -0.5539                       -6.7855 -     3.8394i
-1.7764e-014                  -6.2172e-015                      -14.8246 +     3.6335i
-1.4211e-014                   7.1054e-015                             0
Column 4
-52.6288 +    53.6435i
11.0517 -    10.5774i
5.1466 -    35.4046i
-14.8246 -     3.6335i

>>norm(Qc*Tc*Qc'-a)
2.3559e-013
```