Is there a function similar to matlabFunction() of MATLAB? Or how to do this in R ?
The function in MATLAB.
syms x
dados = inputdlg({'P(x): ', 'Q(x): ', 'R(x): ', 'N: '},'Dados');
P = matlabFunction(sym(dados{1}),'vars',x,'file','px');
In R I'm trying to do it like this:
P <- function(x){
expr = dados[1]
y <- eval(parse(text= expr), list(x))
return (y)
}
But I still have to change the expression inside the function or pass it by parameter.
In Matlab the inline function is equivalent to the matlabFunction() function and in R the function command can be used to create the same functions.
Using both functions in Matlab to prove similarity:
f1 = inline('sin(x/3) - cos(x/5)')
f1 =
Inline function:
f1(x) = sin(x/3) - cos(x/5)
f2 = matlabFunction(sin(x/3) - cos(x/5))
f2 =
@(x)-cos(x.*(1.0./5.0))+sin(x.*(1.0./3.0))
Calling f1 and f2 to compute and prove that sine (2/3) - cosine (2/5) equals -0,3027 in any of the functions:
f1(2)
ans =
-0.3027
f2(2)
ans =
-0.3027
Now the same function created similarly in R :
f <- function(x) sin(x/3) - cos(x/5)
f(2)
-0.3026912
I solved the problem as follows:
make.Rfunction <- function(expressao) {
fn <- function(x) {
return(eval(parse(text= expressao), list(x)))
}
return(fn)
}
dados <- c("x+2")
P <- make.Rfunction(dados[1])
P(2) # resposta : [1] 4
P(3) # resposta : [1] 5