### 5.87 SetMatrix

• SetMatrix( <[z1, z2, z3]> ).
• Description: that function modifies the current matrix (The matrix affects all the graphical elements except axes and grids in the actual version). That matrix represents the analytic expression of an affine plane map, this is a three complex list: $z1$ is the translation vector affix, $z2$ is the matrix’s first column vector affix of the linear part in the base (1,i), and $z3$ is the matrix’s second column vector of the linear part. For example, the identity matrix is written: [0,1,i] (this is the default matrix). (See also GetMatrix, ComposeMatrix, and IdMatrix)
• Exemple(s): si $f:z↦f\left(z\right)$ is an affine map, then its matrix is $\left[f\left(0\right),f\left(1\right)-f\left(0\right),f\left(i\right)-f\left(0\right)\right]$, the calculation can be done by the macro matrix() from TeXgraph.mac: SetMatrix(matrix(i*bar(z))) affects the orthogonal symmetry matrix relative to the first bisecting.

 \begin{texgraph}[name=SetMatrix, export=pgf]   view(-5,5,-3,3), size(7.5),   SetMatrix([0,1,1+i]), axes(0,1+i),   tMin:=-5, tMax:=5,   Color:=red, Width:=8, Cartesienne(2*sin(x)),   Color:=black, Arrows:=2,   tangente(2*sin(x), pi/2, 1.5),   Arrows:=0, LineStyle:=dotted,   Ligne( [2*i,pi/2+2*i, pi/2], 0),   Point(pi/2+2*i),   LabelDot( pi/2, "$\frac{\pi}2$","S",1),   IdMatrix()   \end{texgraph}

Non orthogonal frame