Java Doc for SignificantFigures.java in  » Template-Engine » ostermillerutils » com » Ostermiller » util » Java Source Code / Java DocumentationJava Source Code and Java Documentation

When parsing a number to determine the number of significant figures, these rules are used:

• Non-zero digits are always significant.
• All zeros between other significant digits are significant.
• All zeros left of the decimal point between a significant digit and the decimal point are significant.
• All trailing zeros to the right of the decimal point are significant.
• If the number is contains no digits other than zero, every zero is significant.

When rounding a number the following rules are used:

• If the greatest insignificant digit is less than five, round down.
• If the greatest insignificant digit is greater than five, round up.
• If the greatest insignificant digit is five and followed by some non-zero digit, round up.
• If the greatest insignificant digit is five and followed only by zeros, and the least significant digit is odd, round up.
• If the greatest insignificant digit is five and followed only by zeros, and the least significant digit is even, round down.

Example of using this class to multiply numbers and display the result with the proper number of significant figures:

 String[] arguments = {"1.0", "2.0", ...}
 SignificantFigures number;
 int sigFigs = Integer.MAX_VALUE;
 double result = 1D;
 for (int i=0; i<arguments.length; i++){
     number = new SignificantFigures(arguments[i]);
     sigFigs = Math.min(sigFigs, number.getNumberSignificantFigures());
     result *= number.doubleValue();
 }
 number = new SignificantFigures(result);
 number.setNumberSignificantFigures(sigFigs);
 System.out.println(number);

Example of using this class to add numbers and display the result with the proper number of significant figures:

 String[] arguments = {"1.0", "2.0", ...}
 SignificantFigures number;
 int leastSD = Integer.MIN_VALUE;
 int mostSD = Integer.MIN_VALUE;
 double result = 0D;
 for (int i=0; i<arguments.length; i++){
     number = new SignificantFigures(arguments[i]);
     leastSD = Math.max(leastSD, number.getLSD());
     mostSD = Math.max(mostSD, number.getMSD());
     result += number.doubleValue();
 }
 number = new SignificantFigures(result);
 number.setLMSD(leastSD, mostSD);
 System.out.println(number);

This method has no effect if this number is not a number or infinity.
Parameters:
  significantFigures - desired number of significant figures.

If this number is not a number or infinity Integer.MIN_VALUE will be returned. the decimal place of the least significant digit.
since:
   ostermillerutils 1.00.00

If this number is not a number or infinity Integer.MIN_VALUE will be returned. the decimal place of the least significant digit.
since:
   ostermillerutils 1.00.00

If this number is not a number or infinity zero will be returned. the number of significant digits in this number.
since:
   ostermillerutils 1.00.00

If all significant digits are removed from this number by truncating to the least significant place, a zero will be created with significant figures from the least to most significant places.

This method has no effect if this number is not a number or infinity.
Parameters:
  leastPlace - the desired place of the least significant digit or Integer.MIN_VALUE to ignore.
Parameters:
  mostPlace - the desired place of the most significant digit or Integer.MIN_VALUE to ignore. this number
since:
   ostermillerutils 1.00.00

It is possible to remove all significant digits from this number which will cause the string representation of this number to become "NaN". This could become a problem if you are adding numbers and the result is close to zero. All of the significant digits may get removed, even though the result could be zero with some number of significant digits. Its is safes to use the setLMSD() method which will make a zero with the appropriate number of significant figures in such instances.

This method has no effect if this number is not a number or infinity.
Parameters:
  place - the desired place of the least significant digit. this number.
since:
   ostermillerutils 1.00.00

This method has no effect if this number is not a number or infinity.
Parameters:
  significantFigures - desired number of significant figures. This number.
since:
   ostermillerutils 1.00.00

A string such as "NaN" or "Infinity" may be returned by this method. representation of this number in scientific notation.
since:
   ostermillerutils 1.00.00

A string such as "NaN" or "Infinity" may be returned by this method. representation of this number.
since:
   ostermillerutils 1.00.00