r - Minimize a function with two variables -

-

i minimize function 2 variables.

first have made function (rba), needed inside function (kvasum) need minimize. values minimized on part of rba.

# data vpk = data.frame(v1 =c(3650000000, 19233, 2211.2, 479.47, 168.46, 83.447, 52.349, 38.738,                      32.34, 29.588), v2 = 1:10) n = nrow(vpk)  # functions minimize   # function returns vector 10 values  rba = function(par){   v <- matrix(ncol = 1, nrow = 10)   (p in 1:10){     k<- ifelse (par[1] < 1-1/p && par[1]>0 && p > par[2] &&  par[2]>0 && par[2]<2, par[2]*p,                     ifelse(par[1] < 1-1/par[2] && par[1] > 0 &&  p < par[2] && par[2]>0 && par[2]<2, -1+(par[1]+1/par[2]),                            ifelse(par[1] > (1 - 1 / max(p,par[2])) &&  par[2]>0 && par[2]<2, -1+p, "error")))     v[p] <- k    }   return(v) }  # function uses function rba, , returns value  kvasum = function(par){   sum( (log(vpk$v1)/log(1/n) - rba(par) )^2) }  # find par[1] , par[2] such kvasum minimized  m1 = optim(par=c(0.1,0.4),kvasum, lower=0)

i've tried use optim function, can't work. non-numeric argument, , have tried can think of. appreciated.

there few problems overall process cause trouble.

first of @user227710 mentions in comments should replace && &. these have different meanings.

now optimiser

it looks want set limits parameters (i.e. known box constraints). in order , use lower argument, need use l-bfgs-b method. when use need specify upper argument well.

the error receive, receive because ifelse statement works when values between 0 , 1 roughly. otherwise, k variable gets value error (which value returned if conditions in ifelse statements false) why 

error in log(vpk$v1)/log(1/n) - rba(par) :    non-numeric argument binary operator

error.

therefore, if specify box constraints accordingly (or maybe have @ ifelse statement because might have coded wrong) seems work perfect:

# data vpk = data.frame(v1 =c(3650000000, 19233, 2211.2, 479.47, 168.46, 83.447, 52.349, 38.738,                        32.34, 29.588), v2 = 1:10) n = nrow(vpk)  # functions minimize   # function returns vector 10 values  rba = function(par){   v <- matrix(ncol = 1, nrow = 10)   (p in 1:10){     k<- ifelse (par[1] < 1-1/p & par[1]>0 & p > par[2] &                    par[2]>0 & par[2]<2, par[2]*p,                 ifelse(par[1] < 1-1/par[2] & par[1] > 0 &                           p < par[2] & par[2]>0 & par[2]<2, -1+(par[1]+1/par[2]),                        ifelse(par[1] > (1 - 1 / max(p,par[2])) &                                  par[2]>0 & par[2]<2, -1+p, "error")))     #i adding line here know why optim failed     if(k=='error') stop('your ifelse function returned error')     v[p] <- k    }   return(v) }  # function uses function rba, , returns value  kvasum = function(par){   sum( (log(vpk$v1)/log(1/n) - rba(par) )^2) }  # find par[1] , par[2] such kvasum minimized  m1 = optim(par=c(0.1,0.4),kvasum, method='l-bfgs-b', lower= c(0.1,0.1), upper=c(0.9,0.9))

output:

> m1 $par [1] 0.1 0.1  $value [1] 171.5774  $counts function gradient         2        2   $convergence [1] 0  $message [1] "convergence: norm of projected gradient <= pgtol"

Comments

Post a Comment

Popular posts from this blog

PHP DOM loadHTML() method unusual warning -

-
i had following code works fine on localhost: $document = new domdocument(); $document->loadhtml($p_result); $form = $document->getelementsbytagname('form')->item(0); // code continues using $form variable after same code updated on outside server, loadhtml() failed , issued warning. warning: domdocument::loadhtml() expects parameter 1 valid path, string given in path/name/to/script.php returned null instead of object code pretty gets fatal error. note contents of $p_result absolutely same on outside server , on localhost. but why displays kind of warning , why not work? doesn't loadhtml() expects argument 1 string in first place? why method expects parameter 1 valid path ? just make clear i'm not calling loadhtmlfile() , i'm calling loadhtml() . thanks. you're affected one of php bugs . issue present in php 5.6.8 , 5.6.9. have affected php version on server, , bug-free version on localhost. the bug forbids null
Read more

python - How to create jsonb index using GIN on SQLAlchemy? -

-
here's current code creating index jsonb. index("mytable_data_idx_id_key", mytable.data['id'].astext, postgresql_using='gin') but got error. sqlalchemy.exc.programmingerror: (psycopg2.programmingerror) data type text has no default operator class access method "gin" hint: must specify operator class index or define default operator class data type. [sql: "create index event_data_idx_id_key on event using gin ((data ->> 'id'))"] is there way create index on sqlalchemy? the postgresql specific sqlalchemy docs @ http://docs.sqlalchemy.org/en/latest/dialects/postgresql.html#operator-classes mention postgresql_ops dictionary provide "operator class" used postgresql, , provide example illustrating use: index('my_index', my_table.c.id, my_table.c.data, postgresql_ops={ 'data': 'text_pattern_ops',
Read more

c# - TransactionScope not rolling back although no complete() is called -

-
i'm using transactionscope rollback transaction fail bool errorreported = false; action<importerrorlog> newerrorcallback = e => { errorreported = true; errorcallback(e); }; using (var transaction = new transactionscope()) { foreach (importtaskdefinition task in taskdefinition) { loader.load(streamfile, newerrorcallback, task.destinationtable, processingtaskid); } if (!errorreported) transaction.complete(); } i'm sure there no transactionscope started ahead or after code. i'm using entity framework insert in db. regardless state of errorreported transaction never rolled in case of error. what missing ? transactionscope sets transaction.current . that's does. wants transacted must @ property. i believe ef each time connection opened reason. probably, connection open when scope installed. open connection inside of scope or enlist manually. ef has nasty "design decision": default opens
Read more