科学符号

Question

I'm writing numbers in a file and they should be looking like this:

  5.22226E+00 -2.31833E-01 -9.28221E-01  5.23851E+00 -2.33228E-01 -9.33804E-01
  5.25481E+00 -2.34622E-01 -9.39387E-01  5.27116E+00 -2.36016E-01 -9.44969E-01
  5.28756E+00  3.65029E-01  9.14477E-01  5.30401E+00  3.66841E-01  9.19016E-01
  5.32051E+00  3.68653E-01  9.23556E-01  5.33707E+00  3.70464E-01  9.28095E-01
  5.35367E+00  3.72276E-01  9.32634E-01  5.37033E+00  3.74088E-01  9.37174E-01

Instead they are:

  5.22226E+00 -2.31833E-01 -9.28221E-01  5.23851E+00 -2.33228E-01 -9.33804E-01
  5.25481E+00 -2.34622E-01 -9.39387E-01  5.27116E+00 -2.36016E-01 -9.44969E-01
  5.28756E+00 3.65029E-01 9.14477E-01  5.30401E+00 3.66841E-01 9.19016E-01
  5.32051E+00 3.68653E-01 9.23556E-01  5.33707E+00 3.70464E-01 9.28095E-01
  5.35367E+00 3.72276E-01 9.32634E-01  5.37033E+00 3.74088E-01 9.37174E-01

The difference is that I'm not inserting a space when the sign is "+". How could I do that?

The code I use is

myNumber.ToString("0.00000E+00", CultureInfo.InvariantCulture);

Answer 1

PadLeft应该很好地完成了这个技巧：

myNumber.ToString("0.00000E+00", CultureInfo.InvariantCulture).PadLeft(12);

Answer 2

The best approach would be to use conditional formatting :

myNumber.ToString(" 0.00000E+00;-0.00000E+00", CultureInfo.InvariantCulture);

An alternative (more verbose) approach:

string s = myNumber.ToString("0.00000E+00", CultureInfo.InvariantCulture);
if (myNumber >= 0)
    s = " " + s;

Answer 3

As you can see here , the semicolon sets the formatting according to positive numbers, then negative.

myNumber.ToString(" 0.00000E+00;-0.00000E+00", CultureInfo.InvariantCulture);

You can also force a + to appear if you want, or change the way the - sign is displayed.