ti basic - How to display a value to the homescreen during a ti-89 titanium program -

in relationship thread, kind of trying have had bit more leeway in this.

my problem working on defining program (for ti-89 titanium) write out definitions of variables. however, considering had indefinite amounts of variables add, thought using define function on , on again waste memory , processing power. thinking save variable variable defined in later portion of program.

prompt x lbl x_d_r x_d_r->q:goto def lbl def define expr(q)[1]=x 

where x_d_r has no assigned value. program supposed use defined string list value x. obvious error came about.

so played around on home screen , program screen bit , came across entry(1) , ans(1). see on ti-83 (or 84) go (if remember correctly)

disp q*1 x->ans(1) 

however ans(1) on ti-89 titanium based upon last answer submitted homescreen. then, ans(1) or entry(1) gets replaced in program that. lucky me, found way avoid this.

prgm expr(char(120)&char(22)&char(97)&char(110)&char(115)&char(40)&char(49)&char(41)) endprgm 

for not know, expressing x->ans(1) way code transmit ans(1) within program without removing code so.

but still not work value needs sent home screen in order record properly. 1 of advantages ti-84 or ti-83 wish still had on titanium. have spent time searching ways how can display values of q home screen within program. far learned functions when used straight home screen return value of q same place. have no way of implementing in actual program function not wish transmit value home screen, , rather useless within program.

secondly have found website details methods of such ways return values homescreen. while method 1 seems hold promise, not seem have way of accessing folder/program. because 1 made , has not shared location on pdf. expr("q"&":stop"), q not evaluated out maybe have rework somehow.

while happening, thought other ideas using paste key within program have no idea how implement stuff found getkey let alone how second , grab buttons factor in.

or somehow have ans(1) someplace else other home screen. preferably i/0 screen maybe other list or data matrix.

anybody have ideas on how relay value homescreen through function, pasting or something, , have program defined earlier define value?

update+1 ok beginning question if maybe making more complex needs be...

after all, going x->x_d_r[1], defined elsewhere. beat x->q:goto def lbl def define expr(q)=x

(or calls history recording program define values?) in terms of processing speed , memory count?

got it. see here trying do.

so explanation of main problem again, wanted able post string value of q defined value of x.

the expr( function quite powerful tool on ti-89 , person in other forum, underestimated it. see person trying

inputstr "function:",f(x) expr(f)→f(x)   

and later answered reworking

inputstr "function", n expr(n & "->f(x)") 

the expression tool expresses in parentheses. during break periods in school today, reworked in head thinking "what if tried rewriting parenthesis out reads expr("x->"&string(q))?

lo-and-behold works. tested fuller version of define get

td() prgm prompt x x_d_r->q expr("x->"&string(q)&"[1]") disp x_d_r[1] delvar x_d_r endprgm 

tried, tested , true. works way. see think happening not within quotes evaluated in expression while the quoted objects expressed , added later in response "&" key. furthermore makes sense if describe more english; "express x stored string of q's respective table".

while variables sake have ways make x_d_r local program without compensating fact x_d_r portion not considered store value when executing x_d_r->q. knowing know do

expr("q"+"x_d_r"&->a) expr("x->"&string(a)-"q"&"[1]") 

in order bypass problem.