children

Subexpressions or terms of symbolic expression

Syntax


children(expr)
children(A)

Description

children(expr) returns a vector containing the child subexpressions of the symbolic expression expr. For example, the child subexpressions of a sum are its terms.

children(A) returns a cell array containing the child subexpressions of each expression in A.

Input Arguments

expr

Symbolic expression, equation, or inequality.

A

Vector or matrix of symbolic expressions, equations, or inequalities.

Examples

Find the child subexpressions of this expression. Child subexpressions of a sum are its terms.

syms x y
children(x^2 + x*y + y^2)
ans =
[ x*y, x^2, y^2]

Find the child subexpressions of this expression. This expression is also a sum, only some terms of that sum are negative.

children(x^2 - x*y - y^2)
ans =
[ -x*y, x^2, -y^2]

The child subexpression of a variable is the variable itself:

children(x)
ans =
x

Create the symbolic expression using sym. With this approach, you do not create symbolic variables corresponding to the terms of the expression. Nevertheless, children finds the terms of the expression:

children(sym('a + b + c'))
ans =
[ a, b, c]

Find the child subexpressions of this equation. The child subexpressions of an equation are the left and right sides of that equation.

syms x y
children(x^2 + x*y == y^2 + 1)
ans =
[ x^2 + y*x, y^2 + 1]

Find the child subexpressions of this inequality. The child subexpressions of an inequality are the left and right sides of that inequality.

children(sin(x) < cos(x))
ans =
[ sin(x), cos(x)]

Call the children function for this matrix. The result is the cell array containing the child subexpressions of each element of the matrix.

syms x y
s = children([x + y, sin(x)*cos(y); x^3 - y^3, exp(x*y^2)])
s = 
    [1x2 sym]    [1x2 sym]
    [1x2 sym]    [1x1 sym]

To access the contents of cells in the cell array, use braces:

s{1:4}
ans =
[ x, y]
 
ans =
[ x^3, -y^3]
 
ans =
[ cos(y), sin(x)]
 
ans =
x*y^2

See Also

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