Thread: Mathematica covert string to number problem - help

Dear all, now I'm study mathematica, and face a problem like this:

I want to covert string "1107.302" to a double number and then do some calculation.

Code:

      a = "1107.302 ";
      Print[a];                 >> Output is 1107.302 
      b=ToExpression[a];     
      Print[b];                 >> Output is 1107.3
      c = b * 2;
      .......

But the ToExpression function lost the number "02", then what can I do? Any suggestions?

Thanks in advance!

Originally Posted by muiz

Dear all, now I'm study mathematica, and face a problem like this:

I want to covert string "1107.302" to a double number and then do some calculation.

Code:

      a = "1107.302 ";
      Print[a];                 >> Output is 1107.302 
      b=ToExpression[a];     
      Print[b];                 >> Output is 1107.3
      c = b * 2;
      .......

But the ToExpression function lost the number "02", then what can I do? Any suggestions?

Thanks in advance!

It is always a good idea to tell us what package/language you are using.

Check default format for the display of numerical data (instead of Print[b] try Print[(b-1107)*1000] )

CB

Thanks very much, CB!

I just new a noteBook and type the following codes:

Code:

      a = "1107.302 ";
      b = ToExpression[a];
      Print[b - 1107];         >> Out put:  0.302 , this is correct
      Print[b];                   >> Out put:  1107.3

Then I want to export the b's value to a temp file, I hope the value should be 1107.302, but actually, it's 1107.3.

What can I do then?

Originally Posted by muiz

Thanks very much, CB!

I just new a noteBook and type the following codes:

Code:

      a = "1107.302 ";
      b = ToExpression[a];
      Print[b - 1107];         >> Out put:  0.302 , this is correct
      Print[b];                   >> Out put:  1107.3

Then I want to export the b's value to a temp file, I hope the value should be 1107.302, but actually, it's 1107.3.

What can I do then?

The value is correct, change the format to something that will show a field width of 10 digits with three after the decimal point. I can't tell you how to do that because I don't run Mathematica, but it will tell you somewhere in the help system.

CB

Thanks, CB. I'm checking in help system.