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Groups > comp.lang.java.programmer > #11198

Re: append() vs. write()

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On 01/10/2012 06:35 PM, Jeff Higgins wrote:
> On 01/10/2012 05:15 PM, Jeff Higgins wrote:
>> On 01/10/2012 04:48 PM, Jeff Higgins wrote:
>>> On 01/10/2012 11:17 AM, Benjamin Trendelkamp-Schroer wrote:
>>>> Hi,
>>>>
>>>> I want to write a method that can write possibly large matrices of
>>>> floating point numbers in scientific notation to human readable ascii
>>>> files. I want to be able to specify the formatting of the floating
>>>> point numbers usins format strings like "%1.8e" or "%2.5f".
>>>>
>> Oops! java.utilFormatter Duh. Sorry, please ignore previous post.
>
> Well,maybe not all is lost.
> PrintWriter does have a printf( String format, Object... args).
> So I guess you can lose the DecimalFormat for the printf.

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Collection;


public class Scratch {

   public static void main(String[] args) throws IOException {

     PrintWriter writer = new PrintWriter(
         new BufferedWriter(
             new FileWriter(args[0])));

     String tableHeader, tableFooter,
     rowHeader, rowFooter, columnSeparator;

     // not intended to compile

     Matrix matrix;
     MatrixRow row;

     writer.print(tableHeader);
     while (matrix.hasRows()) {
       row = matrix.nextRow();
       writer.print(rowHeader);
       while (row.hasNextCell()) {
         printFormattedCellValue(
 
writer,row.nextCell().doubleValue(),row.rowIndex,row.columnIndex);
         writer.print(columnSeparator);
       }
       writer.append(rowFooter);
     }
     writer.append(tableFooter);
   }
}
/* probably in your Matrix class

void printFormattedCellValue(
   PrintWriter writer, double value, int rowIndex, int columnIndex) {

   // apply a format depending upon rowIndex and columnIndex
   String format;
   Object[] args;
   writer.printf(format,value,args[0]...);
}
*/

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Thread

append() vs. write() Benjamin Trendelkamp-Schroer <benjamin.trendelkampschroer@googlemail.com> - 2012-01-10 08:17 -0800
  Re: append() vs. write() Jeff Higgins <jeff@invalid.invalid> - 2012-01-10 13:14 -0500
  Re: append() vs. write() markspace <-@.> - 2012-01-10 13:30 -0800
  Re: append() vs. write() Jeff Higgins <jeff@invalid.invalid> - 2012-01-10 16:48 -0500
    Re: append() vs. write() Jeff Higgins <jeff@invalid.invalid> - 2012-01-10 17:15 -0500
      Re: append() vs. write() Jeff Higgins <jeff@invalid.invalid> - 2012-01-10 18:35 -0500
        Re: append() vs. write() Jeff Higgins <jeff@invalid.invalid> - 2012-01-10 19:01 -0500
  Re: append() vs. write() Lew <noone@lewscanon.com> - 2012-01-10 18:06 -0800

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