trace

trace('''var#1''','''var#2''',...,'''var#n''') trace evaluations through the [Output window|Output window].

Returns a string containing the value of the arguments with output order and surrounding text specified by first argument. Specifying of the first text argument is optional.

trace(...) it's a function introduced to help users with script's debug.

==Syntax==

if '''var#1''' is not a text, trace(...) returns comma separated values

{{{{[image|example|{UP}trace%2ftrace_wiki_01.png]}}}}

if '''var#1''' is a text, trace(...) returns the string (no other values)

{{{{[image|example|{UP}trace%2ftrace_wiki_02.png]}}}}

if '''var#1''' is a trace-formatted text, trace(...) returns a string according with '''var#1''' pattern.

to show variable values with custom text/order you must insert into curly brackets the trace() ''variable position index'';

''variable position index'' is '''0''' for '''var#2''', '''1''' for '''var#3''', '''2''' for '''var#4''', etc...

{{{{[image|example|{UP}trace%2ftrace_wiki_03.png]}}}}

{{{{NOTE: curly brackets can be added typing "shift" + "&#0091;" for "&#0123;" and "shift" + "&#0093;" for "&#0125;"}}}}

trace(...) output can force evaluation, placing before the position index:

* '''S:''' for symbolic evaluation

* '''N:''' for numeric evaluation

{{{{[image|example|{UP}trace%2ftrace_wiki_04.png]}}}}

==Usage==

trace() can be used:

* directly, like a common function requiring numerical (=) or symbolical (&rarr;) evaluation

* directly, inside [while|while loops]

* directly, inside [for|for loops] (at least one operation must be performed inside the loop)

* directly, inside [line|line()] (at least one operation must be performed inside the line())

* inside [User functions|user-defined functions]


==History==

* SMath [http://en.smath.info/forum/default.aspx?g=posts&m=6060|0.91] (stable): first relase

==See also==

* [Output window|Output window]

==References==

* trace syntax tutorial [{UP}trace/trace syntax tutorial.zip|trace syntax tutorial.zip]

* trace usage tutorial [{UP}trace/trace usage tutorial.zip|trace usage tutorial.zip]