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matlabprintf

matlab fprintf with formatspec based on value

Say I want to print two numbers

1.755
1.234e-5

For the former, I would write

fprintf('%.3f', 1.755)

and for the latter

fprintf('%.3e', 1.234e-5)

Clearly, the first formatspec does not make sense for 1.234e-5 as it would be printed as 0.000

Is there a way to let matlab deduce an "optimal" best formatspec based on the value to be printed or must this be hardcoded by if-statements?

Solution

  • You probably want %.4g. The format specification %g is defined in the documentation as

    The more compact of %e or %f, with no trailing zeros (Use a precision operator to specify the number of significant digits.)

    Note that, as indicated, with %g the specified precision refers to the number of significant digits (whereas with %f or %e it would be the amount of digits to the right of the decimal point).