1 // Copyright 2020 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package strconv 6 7 // FormatComplex converts the complex number c to a string of the 8 // form (a+bi) where a and b are the real and imaginary parts, 9 // formatted according to the format fmt and precision prec. 10 // 11 // The format fmt and precision prec have the same meaning as in FormatFloat. 12 // It rounds the result assuming that the original was obtained from a complex 13 // value of bitSize bits, which must be 64 for complex64 and 128 for complex128. 14 func FormatComplex(c complex128, fmt byte, prec, bitSize int) string { 15 if bitSize != 64 && bitSize != 128 { 16 panic("invalid bitSize") 17 } 18 bitSize >>= 1 // complex64 uses float32 internally 19 20 // Check if imaginary part has a sign. If not, add one. 21 im := FormatFloat(imag(c), fmt, prec, bitSize) 22 if im[0] != '+' && im[0] != '-' { 23 im = "+" + im 24 } 25 26 return "(" + FormatFloat(real(c), fmt, prec, bitSize) + im + "i)" 27 } 28