pentaho/pentaho-kettle · error · KettleValueException

Function ATAN2 only works with numbers

Error message

Function ATAN2 only works with numbers

What it means

The atan2(Value arg0) method computes the two-argument arc tangent of this Value and arg0. Both operands must be numeric; if this Value is not numeric the method throws this KettleValueException. Note the check is on the receiver Value, so a String receiver (or a non-numeric argument implicitly converted) triggers the throw.

Solutions

1. Ensure both the receiver Value and arg0 are numeric (setType(VALUE_TYPE_NUMBER) or stream-level conversion)
2. Fix the input step metadata so both columns are Number
3. Guard with isNumeric() on both operands before invoking atan2

Example fix

// before
Value angle = y.atan2(x); // y and x are Strings
// after
y.setType(Value.VALUE_TYPE_NUMBER);
x.setType(Value.VALUE_TYPE_NUMBER);
Value angle = y.atan2(x);

if (value == null || arg0 == null || !value.isNumeric() || !arg0.isNumeric()) {
  throw new IllegalArgumentException("ATAN2 requires numeric values for both operands");
}

boolean bothNumeric(Value a, Value b) { return a != null && b != null && a.isNumeric() && b.isNumeric(); }

try {
  result = value.atan2(arg0);
} catch (KettleValueException e) {
  value.setType(Value.VALUE_TYPE_NUMBER);
  arg0.setType(Value.VALUE_TYPE_NUMBER);
  result = value.atan2(arg0);
}

When it happens

Trigger: Calling value.atan2(arg0) where the receiving Value is a non-numeric type (String/Date/Boolean), e.g. computing an angle from two fields read as text.

Common situations: Cartesian-to-polar conversions in transformations where x/y columns come from CSV as String; unconverted fields after a step-reordering refactor.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Function ACOS only works with numeric data
• Function ASIN only works with numeric data
• Function ATAN only works with numeric data
• Function CEIL only works with a number
• Function COS only works with a number

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/fe1496cde68d3eca. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/pentaho/di/compatibility/Value.java:2428

      throw new KettleValueException( "Function ATAN only works with numeric data" );
    }
    return this;
  }

  // implement the ATAN2 function, arguments in args[]
  public Value atan2( Value arg0 ) throws KettleValueException {
    return atan2( arg0.getNumber() );
  }

  public Value atan2( double arg0 ) throws KettleValueException {
    if ( isNull() ) {
      return this;
    }

    if ( isNumeric() ) {
      setValue( Math.atan2( getNumber(), arg0 ) );
    } else {
      throw new KettleValueException( "Function ATAN2 only works with numbers" );
    }
    return this;
  }

  // implement the CEIL function, arguments in args[]
  public Value ceil() throws KettleValueException {
    if ( isNull() ) {
      return this;
    }

    if ( isNumeric() ) {
      setValue( Math.ceil( getNumber() ) );
    } else {
      throw new KettleValueException( "Function CEIL only works with a number" );
    }
    return this;
  }

View on GitHub (pinned to f3058517a1)