symType
Determine type of symbolic object
Syntax
Description
Examples
Symbolic Number
Create a symbolic number and determine its type.
a = sym('3/9');
s = symType(a)
s = "rational"
Now construct a symbolic array by including symbolic numbers in the array elements. Determine the symbolic type of each array element.
B = [-5, a, vpa(a), 1i, pi]; s = symType(B)
s = 1x5 string
"integer" "rational" "vpareal" "complex" "constant"
Symbolic Function or Expression
Create a symbolic function f(x)
using syms
.
syms f(x)
Determine the type of the function. Because f(x)
is an unassigned symbolic function, it has the symbolic type "symfun"
.
s = symType(f)
s = "symfun"
Assigning a mathematical expression to f(x)
changes its symbolic type.
f(x) = x^2; s = symType(f)
s = "expression"
Now check the symbolic type of f(x) = x
and its derivative.
f(x) = x; s = symType(f)
s = "variable"
s = symType(diff(f))
s = "integer"
Inequalities and Solutions
Determine the type of various symbolic objects when solving for inequalities.
Create a quadratic function.
syms y(x)
y(x) = 100 - 5*x^2
y(x) =
Set two inequalities to the quadratic function. Check the symbolic type of each inequality.
eq1 = y(x) > 10; eq2 = x > 2; s = symType([eq1 eq2])
s = 1x2 string
"equation" "equation"
Solve the inequalities using solve
. Return the solutions by setting 'ReturnConditions'
to true
.
eqSol = solve([eq1 eq2], 'ReturnConditions', true);
sols = eqSol.conditions
sols =
Determine the symbolic type of the solutions.
s = symType(sols)
s = "logicalexpression"
Input Arguments
symObj
— Symbolic objects
symbolic numbers | symbolic variables | symbolic expressions | symbolic functions | symbolic units
Symbolic objects, specified as symbolic numbers, symbolic variables, symbolic expressions, symbolic functions, or symbolic units.
Output Arguments
s
— Symbolic types
string array
Symbolic types, returned as a string array. This table shows output values for various symbolic objects.
Output | Description | Input Example |
---|---|---|
"integer" | symbolic integer number | symType(sym('-1')) |
"rational" | symbolic rational number | symType(sym('1/2')) |
"vpareal" | symbolic variable-precision floating-point real number | symType([sym('1.5') vpa('3/2')]) |
"complex" | symbolic complex number | symType(sym('1+2i')) |
"constant" | symbolic mathematical constant | symType(sym([pi catalan])) |
"variable" | symbolic variable | syms x; symType(x) |
"symfun" | unassigned symbolic function | syms f(x); symType(f) |
"expression" | symbolic expression | syms x; symType(sqrt(x)) |
"equation" | symbolic equation and inequality | syms x; symType(x>=0) |
"unit" | symbolic unit | symType(symunit('meter')) |
"logicalexpression" | symbolic logical expression | syms x y; symType(x|y) |
"logicalconstant" | symbolic logical constant | symType([symtrue symfalse]) |
"unsupported" | symbolic object not supported by symType |
Version History
Introduced in R2019a
See Also
sym
| syms
| symfun
| isSymType
| symFunType
| hasSymType
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