// Copyright 2020 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package strconv // FormatComplex converts the complex number c to a string of the // form (a+bi) where a and b are the real and imaginary parts, // formatted according to the format fmt and precision prec. // // The format fmt and precision prec have the same meaning as in FormatFloat. // It rounds the result assuming that the original was obtained from a complex // value of bitSize bits, which must be 64 for complex64 and 128 for complex128. func FormatComplex(c complex128, fmt byte, prec, bitSize int) string { if bitSize != 64 && bitSize != 128 { panic("invalid bitSize") } bitSize >>= 1 // complex64 uses float32 internally // Check if imaginary part has a sign. If not, add one. im := FormatFloat(imag(c), fmt, prec, bitSize) if im[0] != '+' && im[0] != '-' { im = "+" + im } return "(" + FormatFloat(real(c), fmt, prec, bitSize) + im + "i)" }