Formatted Output

ccalc supports C-style formatted output via fprintf and sprintf, matching Octave/MATLAB semantics.

`fprintf` — print to stdout

fprintf(fmt, v1, v2, ...)

Prints formatted text to stdout. No return value — result display is suppressed. No newline is added automatically; include \n explicitly.

fprintf('pi = %.4f\n', pi)         % pi = 3.1416
fprintf('n = %d items\n', 42)      % n = 42 items

`sprintf` — format to string

s = sprintf(fmt, v1, v2, ...)

Same format engine as fprintf, but returns the result as a char array instead of printing it.

label = sprintf('R = %.1f Ohm', 47.5);
disp(label)      % R = 47.5 Ohm

Format specifiers

Specifier	Meaning
`%d`, `%i`	Integer (value truncated to whole number)
`%f`	Fixed-point decimal, default 6 places
`%e`	Scientific notation (`1.23e+04`)
`%g`	Shorter of `%f` and `%e`
`%s`	String (char array or string object)
`%%`	Literal `%`

Width, precision, and flags

The general form is:

%[flags][width][.precision]specifier

Flag	Meaning
`-`	Left-align within field width
`+`	Always show sign (+ or −)
`0`	Zero-pad to field width
	Space in place of `+` for non-negative values

Examples:

fprintf('%8.3f\n',   pi)     %      3.142
fprintf('%-10s|\n', 'hi')    % hi        |
fprintf('%+.4e\n', 1000)     % +1.0000e+03
fprintf('%05d\n',    42)     % 00042
fprintf('% d\n',      5)     %  5

Escape sequences

Sequence	Character
`\n`	Newline
`\t`	Tab
`\\`	Backslash

Multiple arguments and repeat behaviour

When there are more arguments than conversion specifiers in the format string, the format string repeats for the remaining arguments (Octave behaviour):

fprintf('%d\n', 1, 2, 3)
% 1
% 2
% 3

fprintf('x=%.1f  y=%.1f\n', 1, 2, 3, 4)
% x=1.0  y=2.0
% x=3.0  y=4.0

Formatted data table example

fprintf('%6s %12s %12s\n', 'time', 'position', 'velocity')
fprintf('%6s %12s %12s\n', '(s)', '(m)', '(m/s)')
fprintf('%s\n', repmat('-', 1, 32))

t = 0:0.5:2;
pos = 0.5 * 9.81 * t.^2;
vel = 9.81 * t;

for k = 1:length(t)
  fprintf('%6.1f %12.3f %12.3f\n', t(k), pos(k), vel(k))
end

Output:

  time     position     velocity
   (s)          (m)        (m/s)
--------------------------------
   0.0        0.000        0.000
   0.5        1.226        4.905
   1.0        4.905        9.810
   1.5       11.036       14.715
   2.0       19.620       19.620

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