complex - basics of complex mathematics
Complex numbers are numbers of the form z = a+b*i, where a and b are real
numbers and i = sqrt(-1), so that i*i = -1.
There are other ways to represent that number. The pair (a,b) of
real numbers may be viewed as a point in the plane, given by X- and
Y-coordinates. This same point may also be described by giving the pair of
real numbers (r,phi), where r is the distance to the origin O, and phi the
angle between the X-axis and the line Oz. Now z = r*exp(i*phi) =
The basic operations are defined on z = a+b*i and w = c+d*i
- addition: z+w = (a+c) + (b+d)*i
- multiplication: z*w = (a*c - b*d) + (a*d + b*c)*i
- division: z/w = ((a*c + b*d)/(c*c + d*d)) + ((b*c - a*d)/(c*c +
Nearly all math function have a complex counterpart but there are
some complex-only functions.
Your C-compiler can work with complex numbers if it supports the C99 standard.
Link with -lm. The imaginary unit is represented by I.
/* check that exp(i * pi) == -1 */
#include <math.h> /* for atan */
double pi = 4 * atan(1.0);
double complex z = cexp(I * pi);
printf("%f + %f * i\n", creal(z), cimag(z));
cabs(3), cacos(3), cacosh(3), carg(3),
casin(3), casinh(3), catan(3), catanh(3),
ccos(3), ccosh(3), cerf(3), cexp(3),
cexp2(3), cimag(3), clog(3), clog10(3),
clog2(3), conj(3), cpow(3), cproj(3),
creal(3), csin(3), csinh(3), csqrt(3),
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