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-rw-r--r--src/math/floor.go56
1 files changed, 56 insertions, 0 deletions
diff --git a/src/math/floor.go b/src/math/floor.go
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+++ b/src/math/floor.go
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+// Copyright 2009-2010 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 math
+
+// Floor returns the greatest integer value less than or equal to x.
+//
+// Special cases are:
+// Floor(±0) = ±0
+// Floor(±Inf) = ±Inf
+// Floor(NaN) = NaN
+func Floor(x float64) float64
+
+func floor(x float64) float64 {
+ if x == 0 || IsNaN(x) || IsInf(x, 0) {
+ return x
+ }
+ if x < 0 {
+ d, fract := Modf(-x)
+ if fract != 0.0 {
+ d = d + 1
+ }
+ return -d
+ }
+ d, _ := Modf(x)
+ return d
+}
+
+// Ceil returns the least integer value greater than or equal to x.
+//
+// Special cases are:
+// Ceil(±0) = ±0
+// Ceil(±Inf) = ±Inf
+// Ceil(NaN) = NaN
+func Ceil(x float64) float64
+
+func ceil(x float64) float64 {
+ return -Floor(-x)
+}
+
+// Trunc returns the integer value of x.
+//
+// Special cases are:
+// Trunc(±0) = ±0
+// Trunc(±Inf) = ±Inf
+// Trunc(NaN) = NaN
+func Trunc(x float64) float64
+
+func trunc(x float64) float64 {
+ if x == 0 || IsNaN(x) || IsInf(x, 0) {
+ return x
+ }
+ d, _ := Modf(x)
+ return d
+}