Shear Matrix

The shear matrix ${\hbox{\sf e}}_{ij}^s$ is obtained from the Identity Matrix by inserting $s$ at $(i,j)$, e.g.,

$${\hbox{\sf e}}_{12}^s =\left[{\matrix{1 & s & 0\cr 0 & 1 & 0\cr 0 & 0 & 1\cr}}\right].$$

See also Elementary Matrix