Using 'Module' inside 'Compile'

[Scott D. Kasen]

While I've worked with Mathematica for quite some time, I'm first
learning the Compile function. Keeping it brief...

Compile the function...

f1 = Compile[{},
Module[{x, temp},
x = 4.;
If[3 > 2, temp = x; Print["temp in 'if' statement: ", temp]];
Print["temp outside 'if' statement: ", temp];
];
];

Calling the function...

f1[]

Produces the following output:

temp in 'if' statement: 4.
temp outside 'if' statement: temp$3107

First, why does the function create a new local variable temp$3107
outside of the 'If' statement? Second, how can I bring the first value
for "temp" outside of the if statement?

Thanks in advance,
Scott Kasen

[Patrick Scheibe]

Hi,

I assume when tmp is not used bevor, then it is *declared* and
*initialized* inside the if block like in C

f1() {
double x = 4.0;
if(3>2) {
double tmp = x;
printf("...",tmp);
}
printf("...",tmp);
}

so why don't you try

f1 = Compile[{}, Module[{x, temp = 0.0}, x = 4.;

If[3 > 2, temp = x; Print["temp in 'if' statement: ", temp]];
Print["temp outside 'if' statement: ", temp];];];

?

Cheers
Patrick