The call,
[expr { sqrt($x) }]returns the square root of $x.If you're using sqrt in connection with the Pythagorean Theorem:
[expr { sqrt( $x * $x + $y * $y ) }]note that Tcl provides a hypot function, which gives a more concise formula:
[expr { hypot( $x, $y ) }]The hypot function is also more robust in that it will get overflow and underflow less often when dealing with very large or very small numbers.See also: isqrt
