gonum / floats

Operations on slices of floats [DEPRECATED]

Gonum

Installation

The core packages of the Gonum suite are written in pure Go with some assembly. Installation is done using go get.

go get -u gonum.org/v1/gonum/...

Supported Go versions

Gonum supports and tests using the gc compiler on the two most recent Go releases on Linux (386, amd64 and arm64), macOS and Windows (both on amd64).

Note that floating point behavior may differ between compiler versions and between architectures due to differences in floating point operation implementations.

Release schedule

The Gonum modules are released on a six-month release schedule, aligned with the Go releases. i.e.: when Go-1.x is released, Gonum-v0.n.0 is released around the same time. Six months after, Go-1.x+1 is released, and Gonum-v0.n+1.0 as well.

The release schedule, based on the current Go release schedule is thus:

• Gonum-v0.n.0: February
• Gonum-v0.n+1.0: August

Build tags

The Gonum packages use a variety of build tags to set non-standard build conditions. Building Gonum applications will work without knowing how to use these tags, but they can be used during testing and to control the use of assembly and CGO code.

The current list of non-internal tags is as follows:

• safe — do not use assembly or unsafe
• bounds — use bounds checks even in internal calls
• noasm — do not use assembly implementations
• tomita — use Tomita, Tanaka, Takahashi pivot choice for maximimal clique calculation, otherwise use random pivot (only in topo package)

Issues

If you find any bugs, feel free to file an issue on the github issue tracker. Discussions on API changes, added features, code review, or similar requests are preferred on the gonum-dev Google Group.

https://groups.google.com/forum/#!forum/gonum-dev

License

Original code is licensed under the Gonum License found in the LICENSE file. Portions of the code are subject to the additional licenses found in THIRD_PARTY_LICENSES. All third party code is licensed either under a BSD or MIT license.

Code in graph/formats/dot is dual licensed Public Domain Dedication and Gonum License, and users are free to choose the license which suits their needs for this code.

The W3C test suites in graph/formats/rdf are distributed under both the W3C Test Suite License and the W3C 3-clause BSD License.

floats's Issues

doesn't compile with go1.8 beta 1

Compiling with go1.8 beta 1 doesn't work.

$ go version
go version go1.8beta1 linux/amd64
$ go install github.com/gonum/floats
# github.com/gonum/internal/asm
usage: asm [options] file.s
Flags:
  -D value
    	predefined symbol with optional simple value -D=identifier=value; can be set multiple times
  -I value
    	include directory; can be set multiple times
  -S	print assembly and machine code
  -debug
    	dump instructions as they are parsed
  -dynlink
    	support references to Go symbols defined in other shared libraries
  -e	no limit on number of errors reported
  -o string
    	output file; default foo.6 for /a/b/c/foo.s on amd64
  -shared
    	generate code that can be linked into a shared library
  -trimpath string
    	remove prefix from recorded source file paths

With go1.7.1 it works ok.

$ go version
go version go1.7.1 linux/amd64
$ go install github.com/gonum/floats
$

Checked on revision 856ee81.

Consider having a Reverse that swaps the elements

Sub and SubTo have confusing doc

The doc for Sub(s, t) states that the first argument is subtracted from the second. This implies that it computes (t-s) when it actually computes (s-t).

Using cumsum from internal/asm

It seems that there is an assembly version of cumsum in https://github.com/gonum/internal/tree/master/asm/f64

Any reason for not using it here yet?

Build difficulties, missing function

I have run go get github.com/gonum/internal/asm then go get github.com/gonum/floats. The latter yields 7 errors that appear to be related to missing assembly functions, see below. Is this an issue or am I doing something wrong?

bash-4.1$ go get github.com/gonum/floats

github.com/gonum/floats

../../go_projects/src/github.com/gonum/floats/floats.go:27: undefined: asm.DaxpyUnitaryTo
../../go_projects/src/github.com/gonum/floats/floats.go:39: undefined: asm.DaxpyUnitaryTo
../../go_projects/src/github.com/gonum/floats/floats.go:56: undefined: asm.DaxpyUnitaryTo
../../go_projects/src/github.com/gonum/floats/floats.go:68: undefined: asm.DaxpyUnitaryTo
../../go_projects/src/github.com/gonum/floats/floats.go:702: undefined: asm.DscalUnitary
../../go_projects/src/github.com/gonum/floats/floats.go:732: undefined: asm.DaxpyUnitaryTo
../../go_projects/src/github.com/gonum/floats/floats.go:744: undefined: asm.DaxpyUnitaryTo

API behavior congruity

The rest of gonum has the property that if a destination slice is nil, a new slice is allocated. floats does not follow this property. Should it?

If so, these are the ones that need it:
AddScaledTo
AddTo
CumProd
CumSum
DivTo
MulTo
SubTo

Remove AddConst

In #27 @btracey mentioned that AddConst should be removed. It is just a wrapper around a simple loop but it is used at a couple of places in gonum (some of them added recently), so it looks like it is doing some service. What is the current opinion on this?