Square number, but keep the sign (in s)

Question

Is there an easy way to keep the sign after squaring the value. I currently have:

float signed_square(float x) {
    if (x > 0) {
        return x * x;
    } else {
        return -(x * x);
    }
}

+3

c math

Saspiron 04 jan. At 1:55 am

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2 answers

druckermanly · Answer 1 · 2015-01-04T02:02:17+0000

As I said in the comments:

float signed_square(float x){
    return x * fabs(x);
}

chux · Answer 2 · 2015-01-04T04:20:04+0000

C99 supplies double copysign(double x, double y)

Functions copysign

produce a x

signed and magnified value y

.

float signed_square(float x) {
  return copysignf(x*x, x);
}