# 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`

)