For this example, consider the sparse matrices for the 3-D beam model subjected to an impulsive point load at its tip in the file sparseBeam.mat.

Extract the sparse matrices from sparseBeam.mat.

load('sparseBeam.mat','M','K','B','F','G','D');

Create the mechss model object by specifying [] for matrix C, since there is no damping.

sys = mechss(M,[],K,B,F,G,D)

Sparse continuous-time second-order model with 3 outputs, 1 inputs, and 3408 nodes.

Use "spy" and "showStateInfo" to inspect model structure. 
Type "properties('mechss')" for a list of model properties. 
Type "help mechssOptions" for available solver options for this model.

The output sys is a mechss model object containing a 3-by-1 array of sparse models with 3408 nodes, 1 input, and 3 outputs.

You can use the spy command to visualize the sparsity of the mechss model object.

spy(sys)

For this example, consider the sparse matrices of the discrete system in the file discreteSOSparse.mat.

Load the sparse matrices from discreteSOSparse.mat.

load('discreteSOSparse.mat','M','C','K','B','F','G','D','ts');

Create the discrete-time mechss model object by specifying the sample time ts.

sys = mechss(M,C,K,B,F,G,D,ts)

Sparse discrete-time second-order model with 1 outputs, 1 inputs, and 28408 nodes.

Use "spy" and "showStateInfo" to inspect model structure. 
Type "properties('mechss')" for a list of model properties. 
Type "help mechssOptions" for available solver options for this model.

The output sys is a discrete-time mechss model object with 28408 nodes, 1 input, and 1 output.

You can use the spy command to visualize the sparsity pattern of the mechss model object. You can right-click on the plot to select matrices to be displayed.

spy(sys)