# 14.2.15 Class Expression¶

- mosek.fusion.Expression¶
Abstract base class for all objects which can be used as linear expressions of the form \(Ax+b.\)

The main use of this class is to store the result of expressions created by the static methods provided by

`Expr`

.- Members:
Expression.eval – Evaluate the expression and push the result onto the work stack.

Expression.getDim – Return the d’th dimension in the expression.

Expression.getND – Return the number of dimensions in the expression.

Expression.getShape – Get the shape of the expression.

Expression.getSize – Return the total number of elements in the expression (the product of the dimensions).

Expression.index – Get a single element in the expression.

Expression.pick – Pick a number of elements from the expression.

Expression.slice – Get a slice of the expression.

Expression.toString – Return a string representation of the expression object.

- Implemented by:

- Expression.eval¶
void eval(WorkStack rs, WorkStack ws, WorkStack xs)

Evaluate the expression and push the result onto the

`rs`

work stack.

- Expression.getDim¶
int getDim(int d)

Return the d’th dimension in the expression.

- Parameters:
`d`

(`int`

)- Return:
(

`int`

)

- Expression.getND¶
int getND()

Return the number of dimensions in the expression.

- Return:
(

`int`

)

- Expression.getShape¶
int[] getShape()

Get the shape of the expression.

- Return:
(

`int`

[])

- Expression.getSize¶
long getSize()

Return the total number of elements in the expression (the product of the dimensions).

- Return:
(

`long`

)

- Expression.index¶
Expression index(int i) Expression index(int[] indexes)

Get a single element in the expression.

- Parameters:
`i`

(`int`

) – Index of the element to pick.`indexes`

(`int`

[]) – Multi-dimensional index of the element to pick.

- Return:

- Expression.pick¶
Expression pick(int[] indexes) Expression pick(int[][] indexrows)

Picks a number of elements from the expression and returns them as a one-dimensional expression.

- Parameters:
`indexes`

(`int`

[]) – Indexes of the elements to pick`indexrows`

(`int`

[][]) – Indexes of the elements to pick. Each row defines a separate multi-dimensional index.

- Return:

- Expression.slice¶
Expression slice(int first, int last) Expression slice(int[] firsta, int[] lasta)

Get a slice of the expression.

- Parameters:
`first`

(`int`

) – Index of the first element in the slice.`last`

(`int`

) – Index of the last element in the slice plus one.`firsta`

(`int`

[]) – Multi-dimensional index of the first element in the slice.`lasta`

(`int`

[]) – Multi-dimensional index of the element after the end of the slice.

- Return:

- Expression.toString¶
String toString()

Return a string representation of the expression object.

- Return:
(

`String`

)