BellNumber java.lang.OutOfMemoryError: Java heap space

[mschessler]

MathParser.org-mXparser version: v.5.0.5
Framework: java

A big value n for the BellNumber Bell(n) leads to an OutOfMemoryError.

public class Tester {

    public static void callApi(String input){
  
      Expression e = new Expression(input);
      e.setVerboseMode();
      if(e.checkSyntax()){
        e.calculate();
      }
    }
  
    public static void main(String[] args){

        callApi("Bell(999999*9999999)");
    }
}

Log:

[mXparser-v.5.0.5]
[][Bell(9999999999999)]
[][Bell(9999999999999)] Starting ...
[][Bell(9999999999999)] Starting calculation loop
[][Bell(9999999999999)] Parsing (1, 5) ---> ( 999999.0 * 9999999.0 ) ... ---> Bell ( 9.999989000001E12 ) ... done
[][Bell(9999999999999)] Parsing (1, 3) ---> ( 9.999989000001E12 ) ... ---> Bell 9.999989000001E12 ... done
[][Bell(9999999999999)] Parsing (0, 1) ---> Bell 9.999989000001E12 ... Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at org.mariuszgromada.math.mxparser.mathcollection.MathFunctions.bellNumber(MathFunctions.java:300)
at org.mariuszgromada.math.mxparser.mathcollection.MathFunctions.bellNumber(MathFunctions.java:328)
at org.mariuszgromada.math.mxparser.Expression.BELL_NUMBER(Expression.java:3558)
at org.mariuszgromada.math.mxparser.Expression.f1ArgCalc(Expression.java:6373)
at org.mariuszgromada.math.mxparser.Expression.calculate(Expression.java:6179)
at org.mariuszgromada.math.mxparser.Expression.calculate(Expression.java:5666)
at Tester.callApi(Tester.java:11)
at Tester.main(Tester.java:17)

I tried other java algorithms found on the web but they also had the same result. So probably should just catch the Exception.

[mariuszgromada]

:-) Thanks!

[mariuszgromada]

Depending on the system configuration - OutOfMemoryError can happen everywhere ... So I will try to catch it at the very beginning, not just to handle bell number.

I will deal with tomorrow :-)

[mschessler]

That is true. Until now I did not find other functions where a short and fast input is enough to run into a OutOfMemoryError (on a default mem. config), but it would be better to catch it on a broader scale.

[mariuszgromada]

Should work now :-)

[mariuszgromada]

Dear @SyrasX - can you contact me on email info@mathparser.org? I want to thank you for your contribution :-)