i'd like to typeset following (jacobian) matrix.
\begin{equation*} J = \begin{bmatrix} \dfrac{\partial \Delta a_{1}}{\partial c_{1}} & \dfrac{\partial \Delta a_{1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta a_{1}}{\partial c_{m}} & \dfrac{\partial \Delta a_{1}}{\partial d_{m}} & \dfrac{\partial \Delta a_{1}}{\partial c_{m+1}} & \dfrac{\partial \Delta a_{1}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta a_{1}}{\partial c_{n-1}} & \dfrac{\partial \Delta a_{1}}{\partial d_{n-1}} \\[3.0ex] \dfrac{\partial \Delta b_{1}}{\partial c_{1}} & \dfrac{\partial \Delta b_{1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta b_{1}}{\partial c_{m}} & \dfrac{\partial \Delta b_{1}}{\partial d_{m}} & \dfrac{\partial \Delta b_{1}}{\partial c_{m+1}} & \dfrac{\partial \Delta b_{1}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta b_{1}}{\partial c_{n-1}} & \dfrac{\partial \Delta b_{1}}{\partial d_{n-1}} \\ \vdots & \vdots & \ddots & \vdots & \vdots & \vdots & \vdots & \ddots & \vdots & \vdots \\ \dfrac{\partial \Delta a_{m}}{\partial c_{1}} & \dfrac{\partial \Delta a_{m}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta a_{m}}{\partial c_{m}} & \dfrac{\partial \Delta a_{m}}{\partial d_{m}} & \dfrac{\partial \Delta a_{m}}{\partial c_{m+1}} & \dfrac{\partial \Delta a_{m}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta a_{m}}{\partial c_{n-1}} & \dfrac{\partial \Delta a_{m}}{\partial d_{n-1}} \\[3.0ex] \dfrac{\partial \Delta b_{m}}{\partial c_{1}} & \dfrac{\partial \Delta b_{m}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta b_{m}}{\partial c_{m}} & \dfrac{\partial \Delta b_{m}}{\partial d_{m}} & \dfrac{\partial \Delta b_{m}}{\partial c_{m+1}} & \dfrac{\partial \Delta b_{m}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta b_{m}}{\partial c_{n-1}} & \dfrac{\partial \Delta b_{m}}{\partial d_{n-1}} \\[3.0ex] \dfrac{\partial \Delta a_{m+1}}{\partial c_{1}} & \dfrac{\partial \Delta a_{m+1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta a_{m+1}}{\partial c_{m}} & \dfrac{\partial \Delta a_{m+1}}{\partial d_{m}} & \dfrac{\partial \Delta a_{m+1}}{\partial c_{m+1}} & \dfrac{\partial \Delta a_{m+1}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta a_{m+1}}{\partial c_{n-1}} & \dfrac{\partial \Delta a_{m+1}}{\partial d_{n-1}} \\[3.0ex] \dfrac{\partial \Delta b_{m+1}}{\partial c_{1}} & \dfrac{\partial \Delta b_{m+1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta b_{m+1}}{\partial c_{m}} & \dfrac{\partial \Delta b_{m+1}}{\partial d_{m}} & \dfrac{\partial \Delta b_{m+1}}{\partial c_{m+1}} & \dfrac{\partial \Delta b_{m+1}}{\partial d_{m+1}} & \ldots & \dfrac{\partial \Delta b_{m+1}}{\partial c_{n-1}} & \dfrac{\partial \Delta b_{m+1}}{\partial d_{n-1}} \\ \vdots & \vdots & \ddots & \vdots & \vdots & \vdots & \vdots & \ddots & \vdots & \vdots \\ \dfrac{\partial \Delta a_{n-1}}{\partial c_{1}} & \dfrac{\partial \Delta a_{n-1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta a_{n-1}}{\partial c_{m}} & \dfrac{\partial \Delta a_{n-1}}{\partial d_{m}} & \dfrac{\partial \Delta a_{n-1}}{\partial c_{n-1}} & \dfrac{\partial \Delta a_{n-1}}{\partial d_{n-1}} & \ldots & \dfrac{\partial \Delta a_{n-1}}{\partial c_{n-1}} & \dfrac{\partial \Delta a_{n-1}}{\partial d_{n-1}} \\[3.0ex] \dfrac{\partial \Delta b_{n-1}}{\partial c_{1}} & \dfrac{\partial \Delta b_{n-1}}{\partial d_{1}} & \ldots & \dfrac{\partial \Delta b_{n-1}}{\partial c_{m}} & \dfrac{\partial \Delta b_{n-1}}{\partial d_{m}} & \dfrac{\partial \Delta b_{n-1}}{\partial c_{n-1}} & \dfrac{\partial \Delta b_{n-1}}{\partial d_{n-1}} & \ldots & \dfrac{\partial \Delta b_{n-1}}{\partial c_{n-1}} & \dfrac{\partial \Delta b_{n-1}}{\partial d_{n-1}} \end{bmatrix} \end{equation*}
unfortunatelly it is wider than a page. the spaces between columns are (seems to me to be) really huge. i guess with propriate settings the matrix would fit into page.
so is there any way in bmatrix enviroment to reduce horizontal spaces between colums? or would you suggest any other approach to make the matrix fit into page.
thank you very much
vita mach-zizka