Symbolic Math Toolbox

findsym

Finds the variables in a symbolic expression or matrix

Syntax

• r = findsym(S)
  r = findsym(S,n)
  

Description

For a symbolic expression or matrix S, findsym(S) returns all symbolic variables in S in alphabetical order, separated by commas. If S does not contain any variables, findsym returns an empty string.

findsym(S,n) returns the n variables alphabetically closest to x. For single-letter variables that are equally close to x in the alphabet, findsym treats the letter that comes later in the alphabet as being "closer."

findsym(S,1) returns the variable closest to x. This is the default symbolic variable, when none is specified, for the subs and diff commands.

Note    A symbolic variable is an alphanumeric name, other than i or j, that begins with an alphabetic character.

Examples

• syms a x y z t
  findsym(sin(pi*t)) 
  ans = t 
  findsym(x+i*y-j*z) 
  ans = x, y, z
  findsym(a+y,1) 
  returns y.
  

See Also
compose, diff, int, limit, taylor

factor

finverse