# Picture 3.11. The problem about paint - часть 3

The excess method illustrated in the picture 3.11 has three own limitations:

1) the variables’ number can not be more than two as soon as in Mathcad there are vectors and matrixes but there are not tensors (three- and so dimensions matrixes)

2) when matrix is excessive dimension the computer refuses to deal with it and it makes a protest as «there is not enough memory»;

3) the calculation (if the excess can be called the calculation) can last to long i.e. for a long time.

Two limitations can be taken off when we go from the method of forming the matrix (the picture 3.11) to the method of excess of the versions. We remember only optimum plan that can be realized by the software. We have done it in our etude number 6 (look at the pictures 6.31 and 6.32).

The excess method turns out indispensable (that is it can not be so unnatural) when the problem is integer but it looses its linearity[13]. In this case traditional methods (for instance the simplex-method) often turn out feeble.

Nevertheless the excess method in Mathcad will be always the misinterpretation of the first water. Mathcad is the program of interpretive type with low speed of realization of initial text. For excess we need not only the compilers but also the compilers optimizing the time of realization the program.